Ask a Dietitian

VITAMIN D: ARE YOU GETTING ENOUGH?

Recently vitamin D has received the spotlight because of the concern that many Canadians may not be getting enough. This is a concern because of the health implications associated with reduced amounts of vitamin D in an individual.

Why should we be concerned? Vitamin D plays an essential role in the bone health for children, adults and preventing fractures in the elderly. There is also evidence that vitamin D can be protective against some forms of cancer such as colectoral and other immune related diseases.

Who is at Risk of Vitamin D deficiency?

• Elderly: As we age production of vitamin D decreases, we are likely to be more housebound and have lower intake of vitamin D rich food sources
• Exclusively breast fed infants: While exclusive breast feeding is the most suitable nourishment up to 6 months, breast milk is low in vitamin D and is not a sufficient source (see below for recommendation).
• Individuals with dark skin: Skin pigmentation affects the ability to produce vitamin D form sunlight. Darker skin produces lower amounts of vitamin D.
• Individuals wearing clothing that cover most of the body
• Those who consume low amounts of vitamin D rich food sources
• Populations that live in locations that are above 37 degrees latitude during winter months (eg. Canada and Northern US)

What do we get Vitamin D from? It can be obtained from our diet and skin exposure to UVB radiation from sunlight.

Dietary Sources: The main natural sources of vitamin D include fatty fish such as salmon and sardines. For the most part we obtain vitamin D in our diet from fortified foods such as:

1. Cow’s milk (eg. Fluid, evaporated and dried – not milk products such as ice cream or cheese)
2. Fortified plant based beverages
3. Margarine
4. Nutritional supplements and meal replacements
5. Infant formulas

Sunlight: Skin exposure to the UVB radiation from the sunlight also is a source of vitamin D. However, during the winter months in Canada, there is not enough UVB from sunlight to produce adequate vitamin D in the skin.

How much Vitamin D do we need? The Dietary Reference Intakes (dietary standard for Canada) suggest:

• Adults <50 yrs: 200 IU/day
• Adults 51-70 yrs: 400 IU/day
• Adults >71 yrs: 600 IU/day
• Adults >71 yrs + Risk of Osteoporosis: 800 IU/day

Should we be taking Supplements?

Many experts believe that the recommendation for adults is too low for preventing health problems, particularly for those over the age of 50 yrs. As ongoing research progresses, the recommendations may be revised. Presently the suggestions are:

• Include vitamin-rich foods in your daily diet. If you are over 50 and/or at “high risk” of low bone density, it is advisable to eat according to the Canada’s Food Guide and take a supplement of 400 IU vitamin D/day.
• Health Canada and Canadian Paediatric Society also advise all exclusively breastfed infants receive a daily supplement that provides 10ug/day (400 IU) vitamin D from birth.
• Those with concerns about their vitamin D status would be wise to talk with their doctors and have a registered dietititan evaluate their diet.

Information from the Canadian Cancer Society and Dietitians of Canada, May 2006