During this long, cold season, many people become deficient in this essential nutrient due to a decrease in sunlight exposure and the general lack of vitamin D in the American diet. So why is it especially important to supplement vitamin D during the winter season?
Let’s start at the basics…
What is Vitamin D?
Popularly known as the “Sunshine Vitamin,” vitamin D is a unique nutrient in that our bodies naturally create it when exposed to sunlight. Its main function is aiding in calcium and phosphorous absorption, an important role with promoting skeletal strength, bone health, and bone density.** Additionally, vitamin D helps to support immune wellness, neuromuscular health, and cellular function.**
Why are so many people deficient in Vitamin D?
According to a 2009 study published by the University of Colorado’s Denver School of Medicine, 75% of Americans do not get enough vitamin D, and unfortunately the demographics that were the lowest included teenage girls and women—people who would benefit from this vitamin greatly. Deficiency in D is also often seen in the elderly (particularly those in nursing homes) and those who generally do not get out in the sun, such as office workers.
Additionally, there is an increase in vitamin D deficiency during the cold winter months, when we find ourselves indoors bundled up from the cold rather than outside in the sunlight. This, paired with the significant lack of fish in most Americans’ diets, leads to an unfortunate decrease of vitamin D levels in the body.
Why supplement Vitamin D?
While sunlight does kick our bodies into vitamin D-producing gear, therein lies the problem: too much sunlight can cause an array of other health problems due to harmful UV radiation. Additionally, we simply cannot create a necessary level of vitamin D through sunlight exposure alone, so supplementing this nutrient though dietary means is often necessary.
According to a 2004 report on Bone Health and Osteoporosis, the Surgeon General stated: “The Surgeon General wants you to know that you can improve your bone health by getting enough calcium, vitamin D, and physical activity.” This can be achieved by increasing vitamin D absorption through dietary means as well as supplementation.
As we age, our bodies’ natural ability to create and absorb vitamin D declines. There are two forms of vitamin D—D2 (ergocalciferol), which is most often found in supplements and added to foods, and D3 (cholecalciferol), which is the more easily absorbed form of vitamin D that is recommended for older people due to its bioavailability. In recent years, Vitamin D3 has seen a great increase in availability as a supplement form.
What are some food sources of Vitamin D?
Foods that are naturally rich in vitamin D include cod liver oil, cold water fish (such as mackerel, salmon, and herring), butter, and egg yolks. Vitamin D2 is often added to foods, which may be labeled as “fortified with vitamin D,” such as milk, yogurt, cheese, and breakfast cereal.
Unfortunately, vegetables are notoriously low in vitamin D. However, the best choices when it comes to veggie-D are dark green, leafy vegetables. You can also find vitamin D in certain mushrooms that have been exposed to sunlight, such as maitake and portabella mushrooms. The amount of vitamin D in mushrooms will be greatly dependent on how much sunlight that mushroom has seen, so there is no set amount of vitamin D that can be found per mushroom.
How do you get your vitamin D during the winter, as well as year-round? Do you have any vitamin D-inspired recipes using foods rich in this nutrient? Share with us in the comments!