What it is?
Did you know Vitamin D is not actually a Vitamin but a prohormone (hormone precursor)! Vitamin D is commonly thought of as the sun vitamin, however, for those who live through Vancouver’s winters, we may not be getting enough of this sunny vitamin. Vitamin D is mainly produced in the skin when exposed to sunlight and is found naturally in many foods. Once absorbed Vitamin D is converted to its active form in the liver and kidneys.
Why we need it?
Once converted to its active form, Vitamin D plays an important role in calcium absorption. This active vitamin helps increase calcium’s absorption in the gut and into our bloodstream while also preventing calcium loss from the kidneys. Both of these nutrients work hard together to help prevent risk of osteoporosis! Vitamin D has also gained a lot of traction for its possible role with the immune system as well as cardiovascular health, mental health, diabetes, cancer and more. During the winter months as flu season begins, Vitamin D levels tend to be lower and sufficient levels of Vitamin D may be necessary for our innate immune system. Vitamin D deficiency is extremely common and groups at risk include: exclusively breastfed infants, premature infants, those with malabsorption conditions such as celiac and IBD, and older adults as our bodies ability to synthesize Vitamin D starts to decline as we age.
So how can you include more Vitamin D in your diet?
Include vitamin D rich foods like fatty fish (salmon, trout), fortified milks and alternatives, eggs, and get outside more. Wild salmon contains up to 900 IU Vitamin D per serving! Food first is our dietitian’s motto, however, Vitamin D deficiency is so common and supplementation may be required especially during the winter. Health Canada has also released statements that up to 90% of Canadians do not receive enough Vitamin D from foods and despite high content of vitamin D in salmon, wild salmon may not be something you are eating daily. For these reason’s I commonly recommend clients supplement their diet with Vitamin D.
How do I choose a supplement?
Look for a supplement with Vitamin D3 as this form is more easily converted to the its active form and has been shown to increase and sustain blood levels longer than Vitamin D2. If you have a breastfed infant be sure to supplement with Vitamin D drops of 400 IU/d. For toddlers aim for 600 IU/d and for adults aim for 1000-2000 IU/d. Vitamin D toxicity is rare as the upper limit for adults is 4000 IU/d. (based on recommendations by Health Canada)