Are you getting enough vitamin D? With the shorter days and colder temperatures during the winter comes the risk of reduced production of this very important nutrient. In fact, a health survey showed that 4% of Canadians aged 6–79 are deficient in vitamin D, while 10% do not have sufficient levels to maintain bone health.
Also known as the “sunshine vitamin,” vitamin D is made when our bare skin is exposed to sunlight. From October through April, many people living in North America, and further away from the Equator, have less exposure to sunlight hours. This can cause less production of vitamin D and ultimately increased risk of deficiency that can lead to numerous health concerns.
Vitamin D has multiple health benefits. It plays an important role in maintaining calcium and phosphorus levels, supports healthy bones and teeth, and reduces the risk of osteoporosis when combined with a healthy diet and regular exercise.
Maintaining sufficient vitamin D levels may also be linked to supporting immune health, prenatal health, mood, and so much more. Here are ways you can support your vitamin D levels this winter.
Although it is very important to get many of our nutrients through the food we eat, this can be difficult with vitamin D. Only small amounts of this nutrient are found in foods such as fatty fish (salmon, tuna, trout), egg yolks, beef liver, fortified milk, cereals, and orange juice.
But wait! Do you like mushrooms? If so, make sure you add some to your plate at your next meal! Research has shown that mushrooms exposed to sunlight are an excellent source of vitamin D2, and when consumed they can increase and maintain blood levels of vitamin D in a healthy range. [2,3]
So look into eating more edible mushrooms and leave your store-bought mushrooms in a sunny spot!
Taking a supplement with vitamin D3 (the preferred form) is one of the best ways to consistently obtain this important nutrient in the winter months. Since supplements are available in various forms, including liquid, softgels, gummies, and tablets, you can find one to best suit your needs.
How much vitamin D do you need? The recommendation for healthy adults is 400–1000 IU per day, with higher dosages advised for adults over 50 and young adults at risk for osteoporosis or conditions that influence vitamin D absorption. 
A blood test to determine your current vitamin D status can help guide how much vitamin D you should be supplementing with each day. Speak with your doctor to find out about your current levels and recommended daily amount.
The skin contains 7-dehydrocholesterol, a form of cholesterol that is converted to vitamin D when exposed to sunlight. Keep in mind, however, that the amount of vitamin D produced when bare skin is exposed to the sun depends on a number of factors such as the time of day, skin colour, and the amount of skin that is exposed.  The general recommendation is 10–20 minutes of daily sun exposure.
So get outside for a nice walk, build a snowman, or go tobogganing – and soak up some vitamin D!
Stephanie Rubino ND
Dr. Stephanie Rubino, ND is a licensed naturopathic doctor who completed her professional training at the Canadian College of Naturopathic Medicine. Her vision is to help others reach optimal health.
Langlois K, Greene-Finestone L, Little J, et al. Vitamin D status of Canadians as measured in the 2007 to 2009 Canadian Health Measures Survey. Health Reports. 2010; 21(1):47-55.
Keegan RJ, Lu Z, Bogusz JM, et al. Photobiology of vitamin D in mushrooms and its bioavailability in humans. Dermato-endocrinology. 2013; 5(1):165-176.
Cardwell G, Bornman JF, James AP. A review of mushrooms as a potential source of dietary vitamin D. Nutrients. 2018; 10(10):1498.
Osteoporosis Canada. Vitamin D. https://osteoporosis.ca/vitamin-d/. Accessed September 13, 2021.
Mostafa WZ, Hegazy RA. Vitamin D and the skin: Focus on a complex relationship: A review. J Adv Res. 2015 Nov;6(6):793-804.