Vitamin D has long been called the sunshine vitamin because it is produced in the skin when it is exposed to UV B rays. The amount of vitamin D produced is affected by a person’s age, whether or not they use sunscreen, and their skin pigmentation (insufficient levels of vitamin D have been found in non-white people).  The season, latitude, and time of day also affect the amount of vitamin D produced in the skin.  In Canada, vitamin D production vanishes from October to March; therefore Canadians must rely on food sources of vitamin D in order to keep high enough levels in their bodies.

Vitamin D’s major role is to keep calcium and phosphate levels needed for good bone health balanced. People with higher levels of vitamin D tend to have fewer fractures and falls and increased muscle strength. Insufficient vitamin D intake can lead to the development of rickets in children and osteoporosis in adults.  Research is also being done in the area of vitamin D and the prevention of certain types of cancer. It may also play a protective role against certain autoimmune diseases.

While it’s recommended to get your vitamins and minerals from food, the current eating pattern recommended by Canada’s Food Guide doesn’t supply enough dietary vitamin D for people over 50 years of age. Healthy adults aged 51-70 years need 10 ug (400 IU) of vitamin D per day and 15 ug (600 IU) per day for adults over 71 years. The current Food Guide recommendations supply about 5 ug (200 IU) of vitamin D from food. In order to achieve the recommended amount of 10 ug (400 IU), Health Canada advises Canadians over the age of 50 take a vitamin D supplement that provides an additional 10 ug (400 IU).

Even though Health Canada is recommending that adults over 50 take a vitamin D supplement, it’s still important to eat foods that are good sources of vitamin D. The only foods that naturally contain vitamin D are fatty fish such as salmon, mackerel, sardines, and tuna, egg yolks, and beef.  The main food sources of vitamin D for Canadians are those that have been fortified with vitamin D like milk, margarine, yogurt and cheese that have been made with fortified milk. Also available are vitamin D fortified juices, soy beverages, and goat’s milk. It’s important to know that the amount of vitamin D in these products may be less than in cow’s milk. 

The bottom line is that it’s difficult for adults over the age of 50 to get the recommended amount of vitamin D on a daily basis without eating unrealistic amounts of some foods. By following Canada’s Food Guide and taking a vitamin D supplement of 10 ug (400 IU) you’ll be sure to meet your vitamin D needs.

Written by: Kelly Fleming, RD as published in the Windsor Star, July 2008.