We All Need Vitamin D

by Eileen Bennewith

Vitamin D is important for absorbing and maintaining healthy levels of calcium. Without sufficient vitamin D, infants and children risk a serious bone disease called rickets, which causes bones to soften and deform. In adults, a lack of vitamin D can lead to osteomalacia, a condition of under-mineralized bones, or osteoporosis, which causes porous bones that fracture easily. We all need adequate vitamin D for strong bones. Vitamin D may also play a role in reducing the risk of many chronic diseases including diabetes, heart disease, multiple sclerosis, tuberculosis and some cancers.

When sunlight hits our bare skin, we make vitamin D. Being sun aware is important to prevent skin cancer. Clothing, glass and sunscreen all block the production of vitamin D by the skin, so in preventing sunburn, we also prevent vitamin D production. In Canada, between October and March, sunlight is at the wrong angle to make vitamin D even when it is shining brightly. Since we cannot rely on sunshine for providing our daily vitamin D, it is important for Canadians to include enough sources of vitamin D in our diet or with supplements so that we can maintain good health.

Debate is ongoing about how much vitamin D you need from your diet when you live in a geographic region like B.C. where sunlight is limited part of the year. Since there are conflicting opinions, and a great deal of new data, the U.S. and Canadian governments jointly commissioned a review process done by Canadian and American scientists overseen by the Institute of Medicine (IOM). The IOM is an independent, non-governmental body in the U.S.

On November 30, 2010, the long awaited results of this review were finally released. The recommendations from the expert committee suggested that almost all age groups needed more vitamin D than was formerly recommended.

The recommendation for infants less than one year old remains the same at 400 IU of vitamin D per day. There are liquid drops of vitamin D supplement for infants and doses range from one single drop to a full 1 ml dropper, depending on the brand. All breastfed infants need 400 IU of vitamin D from the drops and so do any formula-fed infants who drink less than 4 cups of formula per day. One cup of formula has 100 IU of vitamin D added.

From age one to age 70, the recommended amount of vitamin D required has increased to a daily intake of 600 IU per day. Adults over 70 years of age are advised to get 800 IU of vitamin D per day. These numbers are public health recommendations for healthy people. People with chronic medical conditions should discuss their personal vitamin D needs with their health care provider.

For most family members over age one, some of their daily vitamin D requirement can come from food, but some people may also need a vitamin D supplement. It is important to discuss your need for vitamin D supplements with your health care provider.

Very few foods contain natural vitamin D. For example, an egg yolk has about 25 IU of vitamin D. Fatty fish like salmon can have 600 IU in a 75 gram serving. Canada’s Food Guide recommends that Canadians eat at least two servings of fish each week.

Other foods have no natural vitamin D, but they are fortified with Vitamin D. There is legislation in Canada that all fluid milk and margarine must be fortified with vitamin D. Some other foods such as goat’s milk, plant-based beverages like soy beverage, and some calcium-fortified orange juices are also allowed to have vitamin D added. Cheese and yogurt can be made with fortified milk but often they are not. Always read the label to see if a product contains added vitamin D.

Cow’s milk has 100 IU of vitamin D per cup added to it. Soy beverage has about 80 IU per cup added and fortified orange juice has about 45 IU per cup of added vitamin D.

Making sure that everyone in the family gets enough vitamin D from food or supplements is important for good health.

Eileen Bennewith is a Registered Dietitian and Community Nutritionist with Child, Youth and Family Community Health at Princess Royal Family Centre, Nanaimo.