Vitamin D is often called the “sunshine vitamin” because of our skin’s natural ability to produce the vitamin with exposure to ultraviolet rays. However, in Canada and other northern climates, research states that sun exposure may be insufficient to produce adequate levels of vitamin D. As a result, much attention from the research community and dieticians has recently been paid to the topic of vitamin D maintenance and supplementation.
Vitamin D is best known for its role in building and maintaining bone density by helping the body absorb calcium and phosphorous. However, the vitamin has in recent years been in the spotlight for its additional purported protective effects that certain studies have shown against some cancers, cardiovascular disease and high blood pressure, type 2 diabetes, and multiple sclerosis. Further research is required to confirm these possible protective effects and to determine the dose at which the effects are achieved. A large randomized, controlled trial (the VITAL study) investigating whether a 2000 IU/day supplement is protective against heart disease, stroke and cancer is underway in the U.S. The study includes 25 875 men and women, with results due in late 2017.
Currently, Health Canada’s published Recommended Daily Allowance (RDA) of vitamin D states children over the age of 1 year and adults up to the age of 70 years include 600 IU/day of vitamin D in their diets. Those under the age of 1 year require only 400 IU/day and those over the age of 70 years require 800 IU/day.
Dieticians of Canada state that most people can adequately obtain the current RDAs for vitamin D through food sources, alone, and may not require supplementation. Food sources of vitamin D include egg yolks and fatty fish such as salmon, mackerel, sardines and tuna. Cow’s milk products and baby formulas are often fortified with vitamin D, as are some soy beverages, juices, and some commercially packaged foods.
If you are concerned that you may required more vitamin D than you lifestyle provides, ask your medical doctor, naturopath, or pharmacist whether you would benefit from vitamin D supplementation.