With colder days upon us, it's a wonder anyone in Winnipeg gets enough vitamin D in the fall and winter, wrapped up as we are, with only the tips of our noses showing.
Vitamin D is both a nutrient we eat and a hormone made by our bodies. It's often referred to as the "sunshine vitamin," because it's produced in the body through a process triggered by exposure to sunlight. When it's summer, it's easy to get this vitamin. Now, the sun is lower in the sky and we've packed away the shorts and T-shirts in favour of huddling indoors where it's warm.
And we're not alone. Researchers estimate that worldwide, one billion people have inadequate levels of vitamin D. Deficiencies can be found in all age groups and ethnicities. Even factors such as using sunscreen, darker skin pigmentation, excess weight and age all reduce our ability to absorb vitamin D from sunlight.
Why is vitamin D deficiency such a concern? Recent research suggests it plays a much larger role in health than originally thought. For a long time, vitamin D has been known to play a key role in helping the body absorb calcium, which is used to build strong bones, help prevent osteoporosis and reduce the risk of fractures from falls.
But vitamin D may also play a role in the prevention of a host of chronic diseases, such as heart disease, diabetes, some cancers, multiple sclerosis and infectious diseases. As a result, it is important to get adequate levels of vitamin D year-round, not just for building stronger bones, but for helping prevent chronic diseases.
Since you won't be getting enough vitamin D from the sun, you need to look to other sources. For example, fatty fish such as salmon and mackerel are natural sources of vitamin D, and dairy products and cereals are fortified with the vitamin. But the simplest way is to take a supplement, considering the limited natural sources of vitamin D.
Researchers and various health organizations debate exactly how much vitamin D we need. Health Canada, for example, currently recommends 600 IU of vitamin D daily for everyone from one year of age to 70 years old, and 800 IU daily for those older than that. The upper limit is 4,000 IU daily.
Manitobans, though, may require a higher minimum during the winter, owing to our short, cold days that make it tougher to absorb vitamin D from the sun. But it is also important to make sure you are getting adequate levels of vitamin D during the summer months. As a result, dietitians working for the Winnipeg Regional Health Authority recommend their clients, adults as well as children over the age of one year, take a minimum of 1,000 IU of vitamin D each day, every day.
The Canadian Cancer Society also recommends this amount for adults, but only during fall and winter. On the other hand, Osteoporosis Canada recommends 400 to 1,000 IU of vitamin D daily for adults 19 to 50 years of age.
These differences can be confusing, so it is always a good idea to talk to your health-care provider if you are still unsure about how much vitamin D you need.
In the end, vitamin D will do wonders for your body. Not only will your teeth and bones be stronger, but your immune system will be stronger. You may be able to shake off the common cold more quickly. Studies are also showing it helps your brain think better, even as you age.
So if you want to protect yourself and grow stronger, enlist the help of Super D -- the humble vitamin D.
Lavonne Harms is a registered dietitian with the Winnipeg Regional Health Authority.