Vitamin D is a fat-soluble vitamin that plays an integral role in nutrition and a healthy body. Vitamin D works alongside calcium to ensure the formation and maintenance of healthy bones. As a supplement, vitamin D has (until recently) taken a back seat to the seemingly more important calcium. A deficiency of vitamin D can lead to rickets in children or osteomalacia, and osteoporosis in adults.
Vitamin D Sources: Sunlight and Food
Vitamin D is a vitamin, but we can also make it from a non-food source: the sun! Fifteen minutes a day during peak hours (with skin exposed) should be enough for fair-skinned individuals, but those who have darker skin, are older, or live at more Northern latitudes might not get enough exposure, especially in the winter. Sometimes vitamin D must be provided in the diet.
Dietary sources of vitamin D are rare. Whole, fatty fish are a good source (packing 300 International Units (IU) of vitamin D per 3.5 ounces). Vegetarian sources include milk is fortified with vitamin D (100 IU per cup[1]). Egg yolks also contain some. Most soy milks are also fortified to levels equivalent to dairy milk.
Other dairy products – such as cheese – are not fortified with vitamin D.
Vitamin D Considerations for Vegetarians and Vegans
Vegetarians and vegans don't seem to be more likely to be deficient in vitamin D than omnivores. But, most people are not getting enough.
For vegetarians and vegans, the major sources of vitamin D are fortified foods. In Canada, cow’s milk and margarine must be fortified with vitamin D, while fortification of other products like soy milk is both optional and restricted to certain foods.
Vegan supplements are available.
Vitamin D Supplement Options
Because vitamin D is a fat-soluble vitamin, it is often packaged in gelatin capsules. Vegetarians should look for a vegetable-based capsule, tablet, or liquid multivitamin supplement.
Some forms of vitamin D are not vegan. The most common form found in supplements is cholecalciferol (vitamin D3) which is derived from sheep's wool.
Vitamin D2, called ergocalciferol, is derived from vegan sources like yeast and mushrooms. There is some debate over the usefulness of D2 versus D3 in the body (many think D3 is superior) but for now, the two are generally considered equal.
The Vitamin D - Cancer Connection
Health Canada recommends finding a supplement with minimum 200IU (5 micrograms, mcg) vitamin D, although recent recommendations from the Canadian Cancer society are 1000 IU daily during the fall and winter(3). Those who are at risk for low vitamin D should take a supplement year-round.
New, higher-dose recommendations are based on the association found between cancer risk and vitamin D. One study found that higher levels of vitamin D in the blood was correlated with a lower risk of developing cancer, while another study showed that pre-menopausal women taking more calcium and vitamin D might be less likely to develop breast cancer before menopause(4).
The Bottom Line
In colder climates and more Northern latitudes, most people (vegetarian or not) do not get enough vitamin D.
Vitamin D helps to maintain healthy bones, and helps to prevent diseases like osteoporosis, and several types of cancer.
The Canadian Cancer Society suggests a supplement of 1000IU daily for those who:
- Are older in age
- Are outside less or are covered up most often by clothing
- Have darker skin
Vegetarians and vegans should choose vegetable-sourced capsules or other gelatin-free supplements, while vegans should seek out Vitamin D2, which is not sourced from sheep's wool.
If you have additional questions about vitamin D or whether you should take a supplement, consult a Registered Dietitian or doctor.
References:
- National Post. Let's all Steal Some Sunshine - it's Good for Us [Internet] 2007 [cited July 8, 2007].
- Natural Health Products Directorate. Health Canada. Compendium of Monographs – Vitamin D
- Health Canada. Vitamin D for people over 50, 2007
- Canadian Cancer Society. Canadian Cancer Society Announces Vitamin D Recommendation
Join the Conversation