Vitamin D, as well as calcium, is essential to preventing osteoporosis and may reduce other health risks such
as diabetes and immune system disorders. While exposure to sunlight provides vitamin D, Canadians are at risk
of seasonal vitamin D deficiency because winter sunlight in northern latitudes above 35º does not contain
enough ultraviolet B for vitamin D production. Milk fortified with vitamin D3 contains 100 IUs per 250 ml
glass. Foods such as margarine, eggs, chicken livers, salmon, sardines, herring, mackerel, swordfish and fish
oils (halibut and cod liver oils) all contain small amounts. Supplementation is necessary to obtain adequate
levels as dietary intake has minimal impact. Most multivitamins provide 400 IUs of vitamin D3. Some calcium
supplements also contain vitamin D3.
Osteoporosis Canada’s new guidelines (July 2010) recommend daily supplements of 400 to 1000 IU for adults
under age 50 without osteoporosis or conditions affecting vitamin D absorption. For adults over 50,
supplements of between 800 and 2000 IU are recommended. For people who need added supplementation to reach
optimal vitamin D levels, doses up to the current “tolerable upper intake level” (2000 IU) are safely taken
without medical supervision. Doses above that require medical supervision. A daily supplement of 800 IU
should be regarded as a minimum dose for all adults with osteoporosis.
New 2010 Vitamin D
recommendations
Frequently Asked Questions
Q. I do not have osteoporosis; how much vitamin D do I
need?
A. If you are under 50, do not have osteoporosis, and do not have a
condition that interferes with vitamin D absorption, Osteoporosis Canada recommends daily supplements of 400
– 1000 IU daily. If you are over 50, supplements of between 800 and 2000 IU are recommended.
Q. I have been diagnosed with osteoporosis; how much vitamin D do
I need?
A. A daily supplement of 800 IU is the minimum dose for adults with
osteoporosis, regardless of age and doses up to 2000 IU are often recommended. Doses above that level may be
prescribed by your doctor.
Q. The suggested range for all ages is quite broad; how do I know
how much vitamin D I actually need?
A. The actual requirements for an individual may vary considerably,
depending on a number of factors, including sunlight exposure, and winter travel to a southern location
(below 35 degrees latitude). Certain medical conditions such as celiac disease increase requirements. For a
healthy individual, the dose ranges suggested are safe, but for more specific recommendations you should
discuss this with a health professional.
Q. What are some conditions that can interfere with vitamin D
absorption?
A. Absorption of vitamin D can be interfered with by the
following:
- Malabsorption syndrome: a condition or disease that causes poor
absorption of vitamins and minerals, including celiac disease; cystic fibrosis; chronic liver disease or
inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
- Having had gastric bypass surgery
Q. Do I need to take these supplements all year
round?
A. Exposure to sunlight does provide vitamin D. But Canadians are at risk
of vitamin D deficiency from October to April because winter sunlight in northern latitudes above 35○ does
not contain enough ultraviolet B for vitamin D to be produced. As one ages, the skin is less able to make
vitamin D from sunlight exposure. There are very few food sources of vitamin D. The only naturally occurring
ones are fatty fish and egg yolks. Milk, margarine, some soy beverages and some orange juices are fortified
with vitamin D. Cheese and yogurt can be made from vitamin D fortified milk. Therefore, those over 50 or
having been diagnosed with osteoporosis are advised to take vitamin D supplements all year round.
Q. Is there a maximum amount I can safely
take?
A. Canadians can safely take daily vitamin D supplements up to the
tolerable upper intake level of 2000 IU; doses above that require medical supervision.
