by Brooklyn Wilton, Northern Ontario School of Medicine dietetic intern

MANITOULIN—Winters in the North can be tough. While there are many new activities to try, the cold and snow often leave us feeling tired and unmotivated. The change in weather during the winter months also changes how we get many important nutrients, including vitamin D.

Due to the low levels of sunlight in the winter, it is very important that vitamin D be obtained from other sources, particularly diet or supplementation. For these reasons, it is important that Canadians are aware of how the body uses vitamin D, and how we can get the amount we need!

Vitamin D allows the body to use calcium and phosphorus; it helps to maintain and build strong teeth and bones. Vitamin D can be made by the body after it is exposed to sunlight. Without the proper amount of vitamin D, calcium and phosphorus levels in the blood are reduced, and calcium may be pulled from the bones. This can lead to development of osteoporosis, or fragile bones. On the other hand, high levels of vitamin D can cause calcium to build up in the body, and may lead to the formation of deposits in the kidney, heart or lungs. You can see that it is important to ensure that you are getting just the right amount of vitamin D.

In Canada, some foods have been fortified to include vitamin D, including margarine, cow’s milk, infant formula, and some orange juices. There aren’t many natural sources of vitamin D; some include egg yolks and fatty fish, such as salmon and trout. It is important that we also get this nutrient from sun exposure, in order to meet the recommended daily levels. However, during the winter months, it can be difficult to reach the recommendation from diet and sunlight alone. It is recommended by Health Canada that all children and adults between the ages of one and seventy get 600IU per day of vitamin D, and 800IU for adults over 70-years-old.

The examples below show how little of this nutrient can be found in certain foods, and how difficult it would be to meet the recommendation through diet alone.

To meet recommendations, Health Canada suggests that people over the age of 50 should take of daily vitamin D supplement of 400 IU. They also state that all Canadians should drink two cups of milk or a fortified soy beverage each day, to contribute to their daily intake.

To ensure that you are getting enough vitamin D, or if you are concerned that you may not be meeting your recommended daily intake, contact your health provider, who will help you determine if supplementation is a good option for you.