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Vitamin D Theory of Autism

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Editor's note:Dr. John Jacob Cannell is a vitamin D expert. We strongly encourage readers to visit his website as linked below for more information on vitamin D and a variety of health benefits such as cancer prevention.

Written by Dr. John Jacob Cannell

Executive Director, The Vitamin D Council

http://www.vitamindcouncil.org 

 

In addition to the current epidemic of vitamin D deficiency, say another epidemic—an epidemic of autism—was upon our children? What if the autism epidemic began at the same time the epidemic of vitamin D deficiency began? What if both epidemics had worsened in unison? What if one theory explained all the unexplained facts about autism? What if both epidemics had the same root cause: sun avoidance? What if both were iatrogenic, that is, medical advice to avoid the sun had caused both epidemics? Be warned, what follows is not light reading—autism is not a light disease.

Does The Vitamin D Theory Best Explain Autism?

The theory that vitamin D deficiency, during pregnancy or childhood, causes autism is just a theory. However, the theory has a plausible mechanism of action, explains all the unexplained facts about autism, subsumes several other theories, implies simple prevention, and is easily disprovable—all components of a useful theory. A genetic lesion (abnormality) in some component of the vitamin D system—a lesion vitamin D's unique pharmacology could overcome—would explain why monozygotic (identical) twins are highly affected while fraternal twins are not. Varying brain levels of activated vitamin D during later life would explain why some identical twins get severe disease while others are barely affected. Falling vitamin D levels over the last 20 years due to sun-avoidance explain autism's rapid increase in incidence during that same time. The very different effects estrogen and testosterone have on vitamin D metabolism may explain why boys are much more likely to get it than girls are. Lower vitamin D levels in blacks may explain their higher rates of autism. The vitamin D theory has tenable explanations for all the epidemiological features of autism.

What's The Risk of Going In The Sun?

The window of opportunity to affect brain development is limited. Time is of the essence if the vitamin D theory of autism is correct. Ask yourself, what is the risk of taking your autistic child outside to play in the sun? What's the risk of pregnant women sunbathing for a few minutes every day? Children always played in the sun before the epidemic of autism; your pregnant grandmother spent time in the sun as well. Physicians considered that sunshine was healthy before the sun-scare, that is, before autism became an epidemic.

 

What Is Autism?

The Autism Society of America (http://www.autism-society.org) describes autism as "a complex developmental disability that typically appears during the first three years of life and is the result of a neurological disorder that affects the normal functioning of the brain, impacting development in the areas of social interaction and communication skills...One should keep in mind however, that autism is a spectrum disorder, and it affects each individual differently and to varying degrees." They estimate that 1.5 million Americans and their families are now affected, a national health crisis, costing about $35 billion annually.

After exhaustive metabolic and genetic evaluations, more than 60% of individuals with autism spectrum disorders are found to have idiopathic disease. 1 Even after the most thorough medical evaluation possible, doctors simply cannot find the cause for their autism.

What are autism's five unexplained features?

Any valid theory of autism must explain the following:

1. Significantly higher concordance (if one has it the other is likely to have it) rates in identical, but not fraternal, twins.

2. Widely-varying symptoms, even among identical twins.

3. Striking 4:1 male to female sex ratio.

4. Increased rates in blacks.

5. Rapid increase in occurrence rates over the last 20 years.

Whatever its genetic roots, and they are strong, autism hardly follows classic genetic inheritance. What is clear is that the genes that control autism confer predisposition, not predestination.

Are autism rates increasing?

Multiple scientific groups have reported greatly increasing rates of autism over the last 20 years. Dr. Hjordis Atladottir, of the University of Aarhus in Denmark, recently reported that hyperactivity and Tourette's syndrome (two other childhood neurodevelopmental disorders) have increased dramatically right along with autism, while a third, childhood obsessive-compulsive disorder, has not changed at all. Why would some childhood neurodevelopmental disorders increase dramatically in such a short time, while another is entirely unchanged? Perhaps something is harming our children's brains, and doing so with increasing frequency. 2 3 4

Professor Gillian Baird, and his colleagues at Guy's and St. Thomas' Foundation Trust in England, recently discovered that about 1 in 88 English children will eventually develop autism. Families caring for autistic children are under more stress than those caring for a child with cystic fibrosis, a fatal illness. The lifetime cost of autism is $3.2 million per case. Not only is autism epidemic, it is catastrophic.

 

The Vitamin D Connection

Six years ago, Professor John McGrath and his colleagues at the University of Queensland in Australia, pointed out that vitamin D, "the neglected neurosteroid," was crucial for proper brain development. In the same paper, they reported that activated vitamin D increases nerve growth factor in the brain and the vitamin D receptor appears in a wide variety of brain tissue quite early in the development of the baby. These two facts alone led them to conclude that vitamin D deficiency "should be examined in more detail as a candidate risk factor for neurodevelopmental...disorders." 5

In 2006, Dr. Alan Kalueff and his colleagues went further, suggesting vitamin D offers "neuroprotection, possible interplay with several brain neurotransmitter system and hormones, as well as regulation of behaviors." In 2007, Dr. Kalueff, now at the National Institutes of Mental Health, reviewed the nootropic (brain-enhancing) properties of vitamin D in even more detail and concluded that the scientific data stress the importance of the mother having enough vitamin D while she is pregnant and the child having enough vitamin D after birth for "normal brain functioning." There is no doubt vitamin D affects the brain, and does so profoundly. 6 7

Predisposition - What Gene Should We Be Looking For?

Given what we know about neurosteroids, in our search for the genetics of autism it is reasonable to search for a gene which:

* is environmentally responsive.

* codes for a systemic steroid that is also a potent neurosteroid.

* profoundly affects brain development

* has had its levels decrease over the same time that autism has increased.

* is affected differently by estrogen and testosterone.

* has levels that are much lower in blacks than in whites.

* explains all the bizarre epidemiology of autism.

A tall order indeed.

Two clues: rare genetic malformations of the vitamin D system

An inborn error of metabolism that causes a rare form of rickets, pseudo-vitamin D deficiency rickets, involves the defective manufacture of activated vitamin D. While no one has assessed afflicted children for signs of autism, these children clearly display autistic markers such as hypotonia (flabby muscles), decreased activity, developmental motor delay, listlessness, and failure to thrive.

Much more interesting is the fact that children with Williams Syndrome (rare congenital disorder due to a missing piece of chromosome seven) often have greatly elevated activated vitamin D levels for several months in early life. They usually present in later life with remarkable sociability, overfriendliness, empathy, and willingness to initiate social interaction—strikingly the opposite personality of autistic children. 8 9

So, abnormally-low activated vitamin D levels produce infants with symptoms of autism while abnormally-high levels produce children with personalities the exact opposite of autism.

What is the role of the vitamin D receptor in autism?

Variations in the DNA sequence of vitamin D receptor are common and called vitamin D receptor (VDR) polymorphisms (many shaped receptors). No one has studied them in autism, but a highly significant association exists between one VDR polymorphism and larger head size. Larger head sizes are common in autism, especially in childhood. 10

 

The Role of Sunlight

Vitamin D intake—are children and pregnant women getting as much as they used to?

No, because sun exposure is much less common today. Furthermore, perhaps because the term, vitamin D, contains the word "vitamin," many people mistakenly assume it is a vitamin. Vitamin D is the only known precursor for a steroid hormone system that, until recent sun-avoidance, always began in the skin, not the mouth. Before the sun-scare, 90% of human vitamin D stores came from skin production, not diet. Large populations of pregnant women and autistic children ingesting small amounts orally, instead of generating large amounts through the skin, are novel to human brain development. 11 12

Obviously, if people are going to put it in their mouths, rather than make it in their skin, oral intake must be adequate enough to make up for decreased skin production. However, the skin's production of vitamin D is rapid and robust, easily exceeding usual dietary sources by a factor of 10. For example, when fair-skinned adults sunbathe in the summer (one, full-body, exposure to ultraviolet light, enough to turn the skin slightly pink) they make about 20,000 units of vitamin D in 20 minutes. A pregnant woman would have to drink 200 glasses of milk or take 50 prenatal multivitamins to do the same. An autistic boy who plays inside the house, instead of outside, would have to take several thousand units of vitamin D to make up for what his skin would have produced had he played outside that day. Holick MFHigh prevalence of vitamin D inadequacy and implications for health. 13 13a

When did medical organizations first tell us to avoid the sun?

In 1989, around the time autism began to rise, the American Medical Association's (AMA) Council on Scientific Affairs first warned about the dangers of sun exposure, advising mothers to "keep infants out of the sun as much as possible." In 1999, when autism rates really exploded, the American Academy of Pediatrics went further, advising mothers always to keep infants out of direct sunlight, use sun-protective clothes and sunblock, and make sure children's activities minimize sunlight exposure. Quite inexplicably, they said there was "no evidence" such "rigorous sun protection" would affect vitamin D levels. By 2002, the Centers for Disease Control (CDC) reported such efforts were quite successful: "protection from sun exposure is reported for a high proportion of children." 14 15 16

Did authorities recommend compensatory vitamin D intakes?

Medical organizations did not plan for the vitamin D deficiency such sun avoidance would predictably induce. For example, when the AMA warned about the dangers of sunlight, they did not even mention that sunlight triggers the formation of vitamin D. Furthermore, medical recommendations for infants, children, young women, and pregnant women, did not change during the decades of sun avoidance: 200 units/day for all infants, children, pregnant women, and young adults—regardless of weight. That is, they did, and still do, recommend the same 200 daily units for a 5-pound infant as they do for a 200-pound pregnant woman. In fact, in 2003, the American Academy of Pediatrics cut their long-standing 400 units/day recommendation in half—apparently to comply with government recommendations—and did so despite warnings from a prominent University of Wisconsin professor of pediatrics, Dr. Frank Greer, and despite their own advice four years earlier that infants and children should avoid sunlight. 17

Have vitamin D levels fallen as autism has increased?

Yes they have, although no linear studies of vitamin D levels over the last 20 years exist. That is, we don't know how successful sun avoidance campaigns have been in lowering vitamin D levels. However, if one assumes that some Americans do follow their government's and physician's advice, then at least some must have had declining vitamin D levels over the last 20 years—unless they took enough supplemental vitamin D to make up for lack of sun exposure. Unfortunately, few take the thousands of daily units needed to do that. What we do know is that vitamin D deficiency, like autism, is now an epidemic.

 

About Vitamin D

How is vitamin D unique?

Among the body's steroid hormone systems, vitamin D certainly is unique. Unlike other steroids, the body cannot create the activated vitamin D it needs directly from cholesterol; all of the body's activated vitamin D must come from simple vitamin D—either made in the skin or taken orally. Besides its endocrine role in maintaining blood calcium, activated vitamin D has multiple independent hormonal functions, if enough of its precursor is available. Like all steroid hormones, activated vitamin D binds to a member of the nuclear hormone receptor superfamily where the complex then acts as a molecular switch to signal its target genes. So far, we know 200 genes (about 0.5% of the human genome) are primary targets of activated vitamin D, and the list is steadily growing. If adequate precursor is available, most organs in the human body produce their own activated vitamin D, have a vitamin D receptor, and regulate their own needs independently. Thus, they do not depend on blood supply of activated vitamin D from the kidney. 18 19

Does human behavior determine vitamin D levels?

The pharmacology contained in this paragraph may be a bit confusing to some, but it is vitally important in understanding vitamin D. It is so important that Professor Reinhold Vieth, of the University of Toronto, wrote an entire chapter about its implications in the most current textbook of vitamin D. Unlike any other steroid hormone, substrate (precursor) concentrations are absolutely rate-limiting for activated vitamin D production. The enzyme that first metabolizes vitamin D in the liver and the enzyme in tissue where activated vitamin D is made both operate below their respective Michaelis-Menten constants throughout the full range of their normal substrate concentrations, i.e. the reactions follow first-order, mass-action, kinetics. In English, this means the more vitamin D made in the skin or taken by mouth, the more vitamin D in your blood, and the more vitamin D in your blood, the more activated vitamin D in your brain. That is, levels of activated vitamin D during brain development directly depend on the mother's vitamin D levels, which in turn, directly depend on the amount of vitamin D the mother makes in her skin or ingests orally. That is, the rate-limiting step for the production of activated vitamin D is totally dependent on human behavior, a situation that is unique among all steroids. Brain concentrations of activated vitamin D literally depend on one's behavior—be it the step into the sun, to the supplements, into the shade, or to the sunscreen.

 

Vitamin D and the Brain

Is vitamin D required for normal brain development?

Yes, Professor John McGrath and Dr. Darryl Eyles of the University of Queensland in Australia have repeatedly warned us that normal brain development depends on adequate amounts of activated vitamin D to orchestrate the cellular architecture of the brain. Both the vitamin D receptor and the enzyme necessary to make activated vitamin D are present in a wide-variety of human brain tissues very early in pregnancy. 20 21

Production of the vitamin D receptor in the developing mammalian brain rises steadily beginning several weeks after conception where activated vitamin D induces the expression of nerve growth factor and stimulates brain cell growth. 22 23

Does maternal vitamin D deficiency injure the developing brain?

We do not know what vitamin D deficiency during pregnancy does to human brains, but we know what it does to rat brains and it is not good. In a series of recent animal experiments, Professor John McGrath, Dr. Darryl Eyles and their Australian group found severe maternal vitamin D deficiency in mother rats produced babies with abnormal apoptosis (normal cell death) and abnormal brain cell proliferation, reduced production of proteins involved in nerve structure, and baby rats who have subtle abnormalities in both learning and memory. 24 25 26 27

Several months ago, Dr. Almeras, Professor Feron, and their group at the University of the Mediterranean in Marseilles found developmental vitamin D deficiency disrupts 36 proteins involved in mammalian brain development. Severe maternal vitamin D deficiency leads to rat pups with increased brain size and enlarged ventricles (chambers in the brain), abnormalities very similar to those found in autistic children. 28 29

Is autism an ongoing, destructive, inflammatory disease process?

Abnormal inflammation is associated with both autism and vitamin D deficiency. For example, autistic individuals show increases in cytokines (inflammatory mediators) that show a striking similarity to the immune processes regulated by vitamin D. 30 31

Both the brain and the blood of autistic individuals show evidence of ongoing chronic inflammation and oxidative stress. That is, the autistic disease process is progressive and probably increasingly destructive. If this ongoing inflammation could be interrupted, the symptoms might improve. Hope for a vitamin D treatment effect lies in activated vitamin D's powerful anti-inflammatory properties. Its administration decreases production of inflammatory cytokines in the brain, which have consistently been associated with brain impairment. Activated vitamin D stimulates neurotrophin release (neurotrophins induce the survival of nerve cells), reduces toxic calcium levels in the brain, and inhibits the production of nitrous oxide (nitrous oxide destroys brain cells). Besides reducing inflammatory cytokines, vitamin D does one more thing: it increases concentrations of glutathione—the brain's master antioxidant. 32 33 34 35 36

Do brains function better with higher vitamin D?

At least five studies have found significant associations between higher vitamin D levels and better intellectual functioning, but they all studied adults. However, a recent report found a very high incidence of vitamin D deficiency among 337 younger individuals with intellectual disabilities. The obvious explanation is that intellectually impaired individuals do not go outdoors as often as higher functioning individuals and thus have lower vitamin D levels. Two groups found the association after controlling for outdoor activities, making it likely that low vitamin D levels per se impair intellectual ability. 37 38 39 40 41 42

Does vitamin D explain the role of vaccines, mercury, and heavy metals?

Vitamin D's role in increasing glutathione levels may explain the link between mercury and other heavy metals, oxidative stress, and autism. For example, activated vitamin D lessens heavy metal induced oxidative injuries in rat brain. The primary route for brain toxicity of most heavy metals is through depletion of glutathione. Besides its function as a master antioxidant, glutathione acts as a chelating (binding) agent to remove heavy metals, like mercury. Autistic individuals have difficulty excreting heavy metals, like mercury. If brain levels of activated vitamin D are too low to employ glutathione properly, and thus unable to remove heavy metals, they may be damaged by heavy metal loads normal children easily excrete. That is, the mercury in Thiomerosol vaccines may have injured vitamin D deficient children while normal children would have easily bound the mercury and excreted it. These studies offer further hope that sun-exposure or vitamin D supplements may help autistic children by increasing glutathione and removing heavy metals. Not only do we have more clues that vitamin D is involved in autism, the vitamin D theory just did something else: it explained two other theories of autism, the mercury accumulation theory and the oxidative stress theory. 43 44 45

It bears repeating that the amount of activated vitamin D in the brain directly depends on the amount of vitamin D made in the skin or ingested orally.

 

Vitamin D Deficiency's Role In Autism

Do children with common rickets show signs of autism?

If vitamin D deficiency caused autism, then children with vitamin D deficient rickets would be at greater risk for the disease. To the best of my knowledge, no studies have looked at the psychiatric profiles of children with vitamin D deficient rickets to look for evidence of autism. However, children with rickets are more likely to be hypotonic (flabby muscle tone), display decreased activity, and have developmental motor delays. Hypotonia is common in children with autism, as is decreased activity, and developmental motor delays are the rule. 46 47 48 49

Does vitamin D explain autism's frequent infections?

Vitamin D deficiency in childhood is associated with an increased risk of infections so the vitamin D theory of autism predicts autistic children would be more prone to infections. A recent study found that children who went on to develop autism were not prone to increased infection in the first two years of their life but they looked at infection rates before the child was diagnosed with autism, not afterwards. Three earlier studies found an increased incidence of infections in children with autism. A Japanese study found a very strong positive correlation between the prevalence of infantile autism in 1-year birth cohorts (groups) and the total number of children hospitalized for pneumonia and bronchiolitis during that cohort's birth year. 50 51 52 53 54 55

Drugs that interfere with vitamin D metabolism—do they cause autism?

The vitamin D theory predicts medications that lower vitamin D levels, if taken during pregnancy, would increase the risk for autism. While little is known about the drugs that interfere with vitamin D metabolism, sodium valproate (Depakote) is one drug that lowers vitamin D levels and the drug has been associated with autism. 56 57

Does vitamin D explain seizures, which are common in autism?

Seizures are very common in autism and activated vitamin D increases the seizure threshold, making brain tissue less likely to seize. A controlled study found vitamin D reduced the incidence of seizures in patients with intractable seizures. 58 59

 

Vitamin D Explains Autism

Why are boys at higher risk?

The reason for the striking 4:1 sex difference is totally unknown. However, there is a clue or two. Estrogen and testosterone have very different effects on vitamin D metabolism. In mid-pregnancy, when brains are rapidly developing, boy brains bathe in testosterone and girl brains bathe in estrogen. The majority of studies have found estrogen has multiple enhancing effects on vitamin D metabolism while testosterone does not. For example, in Feldman's massive textbook on vitamin D, Dr. Epstein and Dr. Schneider report, "the majority of studies have found a positive effect of estrogen on activated vitamin D levels." Yet, after reviewing similar studies on testosterone they conclude that "it is unlikely that testosterone is a major controlling factor in vitamin D metabolism." If estrogen potentiates activated vitamin D, but testosterone does not, the differences in sex steroids during brain development may mean that estrogen protects developing female brains from vitamin D deficiencies, while testosterone exposes male brains to those same deficiencies. This is important because any good theory must be parsimonious (explain all known facts). 60

Does vitamin D-rich fish prevent autism?

The vitamin D theory of autism predicts that eating vitamin D-rich fatty ocean fish during pregnancy would improve the offspring's mental abilities—that is as long as that fish did not contain a lot of mercury. Higher fish consumption during pregnancy was associated with better infant cognition, with the greatest effect for infants whose mothers consumed the most fish. Very recently in a Lancet article, Dr. Joseph Hibbeln and colleagues at the National Institutes of Health found low maternal seafood consumption was associated with infants with an increased-risk of lower verbal IQs and poor outcomes for social behaviors, fine motor skills, communication, and social development—outcomes eerily similar to autism. We don't know what in ocean fish helped, omega-3 or vitamin D, but this evidence from a completely different source could support the vitamin D theory of autism. 61 62

Is autism less-common at the equator?

If vitamin D played a role in autism, the disorder should be less common at latitudes closer to the equator, at least before modern sun-avoidance. Dr. William Grant of SUNARC (http://www.sunarc.org) found a strong positive association between latitude and the prevalence of autism in children born in various countries born before 1985, but not after. Recently, the Centers for Disease Control (CDC) in Atlanta reported the autism rates from 14 states. The state with the highest prevalence, New Jersey, is the second most northern state. Alabama, with the lowest prevalence, is the most southern of the 14 states surveyed. Studies of season-of-birth and autism are contradictory, as would be expected if activated vitamin D deficiencies can impair brain development during either pregnancy or in early childhood. However, most studies show excessive autism births in the winter—especially March—when vitamin D levels are at their lowest. 63 64 65

Sunscreen—Does It Increase Risk?

If prenatal or postnatal vitamin D deficiency caused autism, then parents who rigorously used sun protection, during pregnancy and for their children, would be more likely to have children with autism. Richer parents are more likely to apply sunscreen to their children, as are parents with a higher education. Although numerous studies, especially early ones, linked higher social class with autism, a certain kind of statistical problem (called ascertainment bias) confuses such associations. Despite identifying the source of the bias, Dr. Tanya Bhasin at the CDC recently again found wealthier parents and more highly educated parents were at higher risk for having an autistic child. It was not at all clear that ascertainment bias explained all her findings. It appears that people who bought into the sun-scare are more likely to have an autistic child. 66 67 68

Why do children first develop signs around the age of weaning?

If children can develop autism after birth, and it's not entirely a genetic brain injury before birth, then autism should be rare before weaning as infant formula contains significant amounts of vitamin D when calculated on a per-pound basis and breast fed babies are supposed to be supplemented with vitamin D. The disease should rapidly progress after weaning, unless the child takes vitamin D supplements or drinks significant amounts of vitamin D fortified milk. A recent prospective study (the only such prospective study in the medical literature) of 87 children, some at high-risk for autism and some not, found that the children who later developed autism appeared entirely normal at 6 months of age. However, around the age of weaning, the children who later developed autism first showed signs of the disease with rapid additional impairments occurring between 14 months–24 months—the same age many toddlers stop drinking vitamin D-enriched formula or milk and begin consuming lots of sodas and juice, which usually contain no vitamin D. 69

 

Evidence Autism Responds To Sunlight and Vitamin D

Do vitamin D-containing multivitamins help children's brains?

Evidence that vitamin D affects mental abilities comes from a series of 14 controlled studies (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=10706232) evaluating the effect of vitamin D-containing multivitamins on childhood intelligence. All 14 studies they reviewed reported small (1–2%) to modest (5–6%) improvements, usually in nonverbal IQ. Lancet published the first study in 1988. More interestingly, most studies showed no effect on the majority of children but very significant effects (15% gains) in about 20% of children, perhaps the vitamin D-deficient subgroup. Something in the multivitamins helped some of the children's brains quite a bit. Was it the vitamin D? 70

Does autism improve in the summer?

If vitamin D was involved in autism, then symptoms might improve in the summer, when vitamin D levels are the highest. To the best of my knowledge, no controlled studies of such seasonality exist. A case study reported dramatic improvements in both sleep and behavioral problems in an autistic Japanese boy in the summer. Others reported significant improvements in autistic behaviors during a summer camp program that included swimming, hiking, boating, and other activities that would increase brain levels of activated vitamin D. 71 72

Can autistic children get better?

We don't know although most do not. However, if vitamin D is involved in autism then young autistic children, whose brains have not been irreparably damaged, may improve if they move to sunnier latitudes, increase their sun exposure, or start consuming more vitamin D in their diet. Consistent with the theory, not all children diagnosed with autism keep that diagnosis in adulthood and a few children either improve spontaneously or improve after one of the numerous treatment programs available. Naturally, any reports of improvement generate suspicion that the initial diagnosis was incorrect—an obvious possibility. A controlled 3-month study of 20 autistic children found that multivitamins with even low doses of vitamin D (150 units) improved symptoms compared to placebo. What would physiological doses of vitamin D do?

 

The Black Community: A Tragic Injustice

Is autism more common in dark-skinned people?

Vitamin D deficiency discriminates based on race, or more precisely, the amount of melanin (pigment) in the skin, which is an effective and ever-present sunscreen. The vitamin D theory of autism predicts that autism is more common in children born to darker-skinned mothers. Such studies are difficult as they raise sensitive social issues although 3 of 4 recent U.S. studies found a higher incidence of autism in black children, sometimes appreciably higher. 73 74 75 76

In Europe, autism rates are higher in children of dark-skinned immigrants. Dr. Gillberg and colleagues reported that the incidence of autism in Sweden for children born to mothers who emigrated from Uganda was 15%—almost 200 times higher than the general population. 77 78 79

The Centers for Disease Control in Atlanta and others report black children have significantly higher rates of mild mental retardation than white children do and socioeconomic factors cannot explain the differences. 80 81

Do Blacks have a higher risk of pregnancy problems?

Several studies indicate black mothers are more likely to give birth to infants who weigh less and low birth weight is a clear risk factor for autism. 82 83 84 85

Black babies have lower Apgar scores. (Apgar tests are ten point examinations done shortly after birth.) Low Apgar scores are associated with both poor vitamin D intake and with autism. 86 87 88

Are black, pregnant women more likely to be vitamin D deficient?

Recent studies of vitamin D deficiency during pregnancy show striking racial inequities in maternal vitamin D levels. Professor Lisa Bodnar of the University of Pittsburg and her colleagues found that only 37% of white women, but only 4% of black women, in the northern United States were vitamin D sufficient in early pregnancy. That is, 96% of pregnant black women and 63% of pregnant white women did not have adequate vitamin D blood levels. Their infants fared little better and showed the same racial inequity. 45% of the pregnant black women and only 2% of the pregnant white women were severely deficient. Prenatal vitamins, virtually all of which contain only 400 IU of vitamin D, offered little protective effect for mother or infant; 90% of the women in the study reported taking them, to little or no effect. 89

Unless infants take enough vitamin D after birth—either via direct supplementation or enriched formula—infant vitamin D levels are remarkably low, with black infants at highest risk. 78% of unsupplemented, breast-fed, Iowa infants had levels less than 11 ng/mL during winter. For those who wonder how vitamin D could be important for brain development—given its very low levels in breast milk—Professors Hollis and Wagner of the Medical University of South Carolina discovered that breast milk is a source of vitamin D that is rich enough to maintain healthy levels in infants—provided the mothers took at least 4,000 units/day. Pregnant women who do not go out into the sun need more vitamin D than is in their prenatal vitamin—much more. 90 91

Are black children at a disadvantage, right from conception?

In 2002, Dr. Shanna Nesby-O'Dell and her colleagues at the CDC found that almost 50% of young, black women of childbearing age had vitamin D levels lower than 15 ng/mL. 12% of black women had levels less than 10 ng/mL, compared to 0.5% of white women. While it is unknown if such low levels approach those seen in the brain-injury animal studies reviewed above, the levels in these young black women are close to undetectable. It may be that white children have a huge, developmental advantage over black children—an advantage that begins immediately after conception. One that has nothing to do with innate ability and everything to do with environment.

 

What Should We Do Right Now?

That is, what do we do while we wait for all the hundreds of studies that need to be done to see if the vitamin D theory is correct? The studies will take years. If we do nothing but just wait, we are continuing an unplanned naturalistic experiment on pregnant women, the brains of their unborn children, and upon autistic individuals. A risk/benefit analysis tells us the risk of doing nothing is potentially great while the risk of treating vitamin D deficiency is minimal, simply good medicine, and the better choice.

So until we know for sure, pregnant women, infants, children, everyone—especially autistic children—should receive sensible sun exposure daily: around noon or 1:00 p.m., expose as much skin as possible, 10–30 minutes duration—depending on how easily one sunburns. In the winter, use a suntan parlor once a week, with the same precautions, or better yet, purchase an ultraviolet vitamin D lamp (http://sperti.com/) for home use.

I prefer to avoid sunlight, what should I do?

You and your child should have a vitamin D blood test, called a 25-hydroxyvitamin D . Then take enough vitamin D to achieve adequate (natural summertime) levels. Given what we do know, adequate 25(OH)D levels are now thought to be somewhere above 40 ng/mL (100 nmol/L) and probably closer 50 ng/mL (125 nmol/L). Ideal levels are unknown but they are probably close to levels that were present when the human genome evolved. Natural levels (levels found in humans who live or work in the sun) are around 50–70 ng/mL (125–175 nmol/L). These levels are obtained by only a small fraction of modern humans. 92 93

How much vitamin D should I take?

The Food and Nutrition Board set the current Upper Limit for medically-unsupervised intake by infants and babies (up to the age of 1 years-old) at 1,000 units/day. This means the government says it is safe to give infants and babies up to 1,000 units a day without getting a blood test. Of course, with correct sun exposure in the summer this is not necessary, but it will be in winter. Children over 1 years of age, according to the Food and Nutrition Board, may safely take 2,000 units/day—again, without requiring a blood test.

For adolescents, pregnant women, and other adults, the government's Upper Limits are a problem. While a 2,000 unit Upper Limit is entirely appropriate for younger children, such limits in heavier adolescents, adults, and pregnant women limit effective treatment of vitamin D deficiency. However, these limits no more impair a physician's ability to treat vitamin D deficiency with higher doses than comparable Upper Limits for calcium or magnesium impair their ability to treat calcium or magnesium deficiencies with higher doses, should those deficiencies be diagnosed. 94

In the absence of sun exposure and in winter, heavier children, adults, and pregnant women may require doses above 2,000 units daily (depending on pre-existing blood levels, body weight, degree of skin pigmentation, age, and latitude of residence) in order to obtain and maintain levels of 50–70 ng/mL. For example, Professor Heaney at Creighton University has estimated that about 3,000 units/day is required simply to assure that 97% of adult Americans obtain levels greater than 35 ng/mL. Healthy adult men utilize up to 5,000 units of vitamin D per day, if present in the body. Professors Bruce Hollis and Carol Wagner, in South Carolina, have been giving pregnant women 4,000 units/day for years. Professor Vieth, at the University of Toronto, found that actual vitamin D toxicity, with systemic symptoms, is exceedingly rare and requires much higher doses than those discussed above. When exceeding the Upper Limit, periodic serum 25(OH)D and calcium levels will reassure both physician and patient that such amounts are safe as well as convince all concerned that the government should revise their ten-year-old (yet most current) recommendations—the sooner the better. 95 96 97 98

Is Autism Iatrogenic?

If the vitamin D theory of autism is correct, then to the extent it is correct, the current plague of autism is an iatrogenic disease, caused by modern sun-avoidance and the organizations that promulgated it. Long before we worshipped our current gods, primitive humans venerated an older god, the sun. Much as we have shunned our modern gods, 20 years ago we shunned the sun, hiding from it under buildings, cars, shade, and sunblock. We told the sun she was damaging us, and banished her from our lives—and from the lives of our pregnant women and our children. Tragically, we relied on medical knowledge instead of human traditions, government recommendations instead of common sense, the latest science instead of basic instincts. The ancient Greeks, who loved the sun, knew the gods seldom reward such hubris.

 

 

 

 

References:

1. Schaefer GB, Lutz RE. Diagnostic yield in the clinical genetic evaluation of autism spectrum disorders. Genet Med. 2006 Sep;8(9):549–56.

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