Canadians should take more vitamin D supplements

Editor's note: Americans too need to take more vitamin D supplements.

Osteoporosis Canada has updated its recommendations on vitamin D intake and now the medical group says adults under the age of 50 years should take a minimum of 400 IU of vitamin D daily and those older than 50 should take at least 800 International Units of vitamin D.

The new OC's 2002 Clinical Practice Guidelines were co-authored by Dr. David Hanley of the University of Calgary Faculty of Medicine, who said the current recommendations on vitamin d intake for Canadians are more than 10 years old and new research has justified the update.

The new guidelines published this week in the online issue of the Canadian medical Association Journal say people who are younger than 50 should take 400 to 1000 IU of vitamin D and those who are older than 50 should take 800 to 2000 IU of vitamin D supplements daily.

Vitamin D is known to help calcium adsorption and vitamin D deficiency is linked with bone disease like osteoporosis.

"Canadians are at risk of vitamin D deficiency from October to April because winter sunlight in northern latitudes does not allow for adequate vitamin D production," said Julie Foley, president & CEO of Osteoporosis Canada.

"Because vitamin D requirements for an individual may vary considerably depending on many factors, it's very important to check with your physician about how much vitamin D you should be taking."

Vitamin D is found only in a few foods including fatty fish, eggs and mushroom.  The main source is sunshine.  It is generally believed that sun exposure of the face and hands at the hottest hours for 15 to 20 minutes can get a person enough vitamin D - 10,000 IU.

Vitamin D deficiency has been linked with a wide range of health conditions including at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, and periodontal disease among others, according to Vitamin D Council.  

Studies have found even for young school children taking 2000 IU of vitamin D per day for a whole year does not seem to cause any side effect.  

Dr. John Cannell, a vitamin D expert and founder of vitamin D Council, suggests on his website that taking 1000 IU or 2000 may not be enough for disease prevention.

He suggests that people should take 5000 IU every day for 2 to 3 months and then have a blood test for 25-hydroxyvitamin D to see if their serum vitamin D levels are in the optimal range. The goal is to have vitamin D between 50–80 ng/mL (or 125–200 nM/L) year-round.

Hanley with co-authors wrote "Canadians can safely take daily vitamin D supplements up to the current definition of tolerable upper intake level (50 mcg [2000 IU]), but doses above that require medical supervision."

Vitamin D toxicity is unlikely in healthy people at intake levels lower than 10,000 IU/day, according to Linus Pauling Institute.

By David Liu