In the Dark About Vitamin D?

June 1, 2009

By Dawn Peacock, BSc, RD
Dawn is a Registered Dietitian at Talisman Centre

Q. "I've been hearing a lot about Vitamin D lately, and how important it is. What's so special about Vitamin D, and should I be taking supplements?"

A. Vitamin D is important for strong bones and research also suggests that it plays a role in the prevention of various diseases such as Multiple Sclerosis, cancer, heart disease and diabetes. However, studies show that many of us are not getting enough of this important "sunshine vitamin", especially during the fall/winter months.


Between the months of October to March, due to low levels of UVB in the winter sunlight, our bodies can’t make Vitamin D and our diets often fall short. There are only a handful of good sources of Vitamin D in our diet, and we don’t often include enough of them to meet our needs. Food sources include fish, milk, fortified soy beverages and food products, egg yolks and margarine.

Foods and Vitamin D Content (IU = International Units)

  • Salmon (wild) – 3 oz   -  1000 IU
  • Salmon (farmed) – 3 oz   -  275 IU
  • Catfish, Mackerel or Trout (farmed) – 3 oz   -  375-415 IU
  • Tuna or Halibut – 3 oz   -  135-170 IU
  • Milk – 1 cup   -  100 IU
  • Cod – 3 oz   -  80 IU
  • Mushrooms (Shitake) – 2 oz   -  55 IU
  • Egg (whole)   -  25 IU
Adapted from: Vitamin D: A Rapid Review. Moyad, M.A. Urologic Nursing, October 2008.

How much do we need?

That depends on who you ask. Many health organizations have differing recommendations. Just looking at 3 Canadian organizations (Health Canada, Osteoporosis Canada, and Canadian Cancer Society) amounts range between 200 – 1000 IU / day. Some of the recommendations may differ based on the time of the year, where we live, skin color, medical condition and age. Getting enough is important, but getting too much can be dangerous. Don’t go over 2000 IU a day without first consulting with your doctor or health care professional.

Did you know there is a blood test for Vitamin D status? If you are curious about whether you’re falling short on Vitamin D, ask your doctor to add this to your regular blood work at your next check-up. It’s the only way to really know if you’re getting enough, and if you’re not, how much Vitamin D you need to take to achieve optimal vitamin D status.

How much vitamin D are you getting in your food choices and supplements? Contact the nutrition services at Talisman Centre, (403) 355-1281, for a full assessment.

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