Vitamin D is a common topic, especially as we transition into fall in Canada and our sun starts to dip a little lower in the sky. But what is it, and why is it so important to include optimal amounts in our daily lives?
One of my most common supplementation recommendations, vitamin D has broad reaching benefits for those who obtain the right amounts through sunshine, food, and a daily supplement!
The beneficial effects of vitamin D are measured once it is in our bodies and converted into its hormonally active form called calcitriol. Calcitriol acts on many systems, and is important for our absorption of calcium, strengthening our immune system, brain development, and maintaining healthy respiratory and cardiovascular systems. Deficiencies in vitamin D have been linked to cancer, asthma, high blood pressure, depression, and even autoimmune disease like multiple sclerosis.
So how do we get it? The purest form of vitamin D comes when large amounts of skin are exposed to a sun high in the sky. In the summer, we can obtain doses from 10,000 to 25,000 IU of vitamin D before our skins begins to burn. 15 minutes of full sun for fair-skinned individuals (with more time needed proportionately to the darkness of your skin), is enough for a daily dose.
In Canada, these conditions only last for around 4 months of the year! Once the sun sits lower in the sky, even sunny days do not provide enough ultraviolet B rays for us to get in our daily dose. This is when supplementation comes in, but once at the vitamin shop, the choices become overwhelming. Here is a quick understanding of what you see:
Vitamin D2 - This type comes from plants, such as mushrooms grown in UV light. It is cheaper to produce, and therefore is the type commonly found in fortified foods. It is absorbed equally as well as D3, but studies have found that is does not raise vitamin D levels in the blood equally (the liver metabolizes the compounds differently, yielding slightly different compounds).