By Andrew Holwegner, Health Stand Nutrition Consulting Inc.
What is it?
Vitamin D is a fat soluble vitamin that is found in food and can also be made in your body after exposure to ultraviolet (UV) rays from the sun. The primary function of vitamin D in the body is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. Without vitamin D, bones can become thin, brittle, soft, or misshapen. Vitamin D prevents rickets in children and osteomalacia in adults, which are skeletal diseases that result in defects that weaken bones.
What are sources of Vitamin D?
Fortified foods such as milk products and breakfast cereals are the major dietary sources of Vitamin D. Foods naturally rich in Vitamin D include the flesh of fatty fish, some fish liver oils, and eggs from hens fed vitamin D. Although milk is fortified with vitamin D, dairy products made from milk, such as cheese and ice creams, are generally not fortified with vitamin D and contain only small amounts.
Food sources of vitamin D
|Food||International Units(IU) per serving|
|Cod liver oil, 1 Tablespoon||1,360|
|Salmon, cooked, 3½ ounces||360|
|Mackerel, cooked, 3½ ounces||345|
|Tuna fish, canned in oil, 3 ounces||200|
|Sardines, canned in oil, drained, 1¾ ounces||250|
|Milk 1 cup||98|
|Margarine, fortified, 1 tablespoon||60|
|Pudding, prepared from mix and made with vitamin D fortified milk, ½ cup||50|
|Ready-to-eat cereals, ¾ cup to 1 cup servings (servings vary according to the brand)||40|
|Egg, 1 whole||20|
|Liver, beef, cooked, 3½ ounces||15|
|Cheese, Swiss, 1 ounce||12|
What is the recommended intake for vitamin D?
The recommended intake is listed as an Adequate Intake (AI), which represents the daily vitamin D intake that should maintain bone health and normal calcium metabolism in healthy people. The need for vitamin D increases after the age of 50 for both men and women. Health Canada recommends that everyone over the age of 50 should take a daily vitamin D supplement of 400 IU.
Adequate Intake for vitamin D for infants, children, and adults1
|Age||Children (IU/day)||Men (IU/day)||Women (IU/day)|
|Birth to 13 years||200 IU|
|14 to 18 years||200 IU||200 IU|
|19 to 50 years||200 IU||200 IU|
|51 to 70 years||400 IU||400 IU|
|71+ years||600 IU||600 IU|
1: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005)
New 2007 Version of Canada’s Food Guide!
On February 5th 2007, Health Canada launched the new 2007 version of Canada’s Food Guide: “Eating Well with Canada’s Food Guide“.
In the new Food Guide, you can find detailed information on the amount and types of food recommended for your age and gender. The new Food Guide encourages Canadians to focus on vegetables, fruit and whole grains, and to include milk, meat and their alternatives, and to limit foods that are high in calories, fat, sugar and salt.
In addition to following Canada’s Food Guide, Health Canada is now recommending a Vitamin D supplement (400 IU) for Canadians over the age of 50, as the need for vitamin D increases after age 50. It is difficult to meet the vitamin D recommendations for people over 50 years of age without recommending unrealistic daily amounts of some foods.
For more information on Canada’s Food Guide, please visit Health Canada’s Web site.