Do I need Vitamin D this winter?

NOTE: This article is not medical advice; it is intended for general information purposes only. Please consult your family physician for advice about your own unique health situation.

Vitamin D is best known for its role in bone health. It helps us absorb calcium from the food we eat and works within bones as they grow and repair themselves. It also plays a role in cell growth, immune function, and inflammation reduction.

It’s difficult to get all the vitamin D we need from diet alone. It naturally occurs in a small number of foods, such as egg yolks, salmon, and other ocean fish and in Canada, vitamin D is also added to other foods, such as milk and margarine.

Exposure to sunshine and supplements are other ways to get vitamin D, often called the sunshine vitamin. When the UVB rays of the sun are absorbed through our skin, a chemical in our skin is changed and becomes inactive Vitamin D. For at least half the year Canada and other northern climates do not have enough sun exposure to give us all the vitamin D we need. Sun exposure has its own risks, the most worrisome is increasing our risk of skin cancer.

For many Islanders, supplements may be a good alternative. The recommended daily dose of vitamin D depends upon age and gender but ranges between 400 – 800 IU. However, because vitamin D is stored, it’s possible to have too much.

It is important to talk to your family doctor about what the best dose of vitamin D is for you, or if you even need to supplement at all.

However we get our Vitamin D, we also need healthy livers and kidneys to turn the inactive type we consume into an active type that our bodies can use.

How do you know if your level of vitamin D is low? Blood levels of vitamin D, specifically, 25-hydroxy-vitamin-D (25(OH)D), can be measured by your doctor. Testing isn’t commonly done though for two reasons: first, as Islanders, we are all deficient unless we are paying attention to the food choices we make, or choosing to use supplements, to get enough vitamin D. The test is unnecessary to confirm we have a deficiency; we all do. Second, unlike other blood levels we don’t use the blood level to guide how much vitamin D we need. This is because vitamin D is stored in our fat cells and only a small amount circulates in our blood.

In addition to watching how much vitamin D we are getting, there are other ways to improve our bone health. First, ensure that your diet contains adequate calcium and magnesium as well as vitamin D. Next, participate in regular weight bearing exercise, like walking. Lastly, make healthy choices concerning alcohol and smoking. Many people are surprised to learn that quitting smoking and reducing alcohol and caffeine consumption also reduce the risk of osteoporosis and pathological bone fractures.

Get the conversation started. Visit the Dietitians of Canada website for information on dietary sources of vitamin D. Discuss bone health with your family doctor and other members of your health care team to determine which steps you can take to improve your bone health.