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How Vitamin D Works


Foods That Contain Vitamin D
It's clear vitamin D is important -- but how do you get it? It's true that vitamin D can be produced naturally via sunlight, but it is also in some common foods. However, some foods are better sources of vitamin D than others.

Few foods contain significant amounts of vitamin D naturally, and the ones that do are not foods you want to overdo: butter, cream, egg yolks, and liver. But there are some good sources. All milk -- including skim milk -- is fortified with vitamin D at a level of 100 IU per cup. Some manufacturers also fortify cereals with vitamin D. Cod liver oil, as a supplement, contains about 1,200 IU of vitamin D per tablespoon. Cod liver oil should be used cautiously as a dietary supplement, however, because it also contains high levels of vitamin A -- that can have toxic effects.

Eggs contain Vitamin D.
©2007 Publications International, Ltd.
Egg yolks are a source of Vitamin D,
but aren't a food that is healthy to
eat in excess.

A fair-skinned person can make a sufficient quantity of vitamin D with only 20 to 30 minutes of sun exposure a day. It would take much more time, about three hours, for a dark-skinned person to make an equal amount of the vitamin because skin pigment filters out UV rays.

You cannot overdose on vitamin D from sun exposure because it limits itself. Of course, you can get too much sun, increasing your risk of skin cancer. Unfortunately, because sunscreens filter out the ultraviolet rays that burn your skin, they block the manufacture of vitamin D as well. Exposing unprotected skin to the sun in the early morning or late afternoon hours solves both problems.

Clouds, smog, clothing, and even window glass also filter out ultraviolet rays. Housebound people, those with dark skin, those that cover most of their skin when outdoors and those who live in cloudy, northern climates are most likely to be deficient in vitamin D. These people must get vitamin D from foods.

Here is a chart you can use to find foods rich in vitamin D:

Sources of Vitamin D
Food Quantity
Vitamin D (mcg)
Tuna salad
1 cup
7.5
Skim milk
1 cup
2.5
Milk 1 cup
2.5
Egg substitute
1/2 cup
2.1
Eggnog 1/2 cup
1.5
Raisin Bran
1 cup
1.4
Total cereal
1 cup
1.2
Product 19
1 cup
1.2
Yogurt, low-fat
1 cup
1.2
Special K
1 cup
1.2

If you don't receive enough vitamin D, there are a number of deficiency issues that can arise. In the next section, we'll discuss the negative effect a lack of vitamin D can have on your bones and body overall.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.