Sunshine in a bottle – now wouldn’t that be nice?
Vitamin D3, or cholecalciferol, is one of the crucial vitamins in our lives that we have mentioned here on the FFF blog (1,2,3). This time of year it is essential to understand the function and importance of this vitamin because there is about the be a whole let less sunshine, making it more difficult to get an abundance of this vitamin naturally.
Vitamin D – What’s It’s Deal
Vitamin D is a vitamin and a hormone. A vitamin is :
“any of a group of organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body.”
A hormone, on the other hand is:
“a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.”
Our main differences here are that vitamins are used for growth and nourishment through food sources, and hormones are produced within the body and act upon the cells of the body causing some form of alteration at the cellular level. Vitamin D is an essential nutrient and vitamin because we cannot make it ourselves. It is also a hormone because our body produces it by altering the Vitamin D3 in the liver, allowing it to control calcium levels in the blood.
What Does Vitamin D do?
Vitamin D is essential for our bone health. Without adequate amounts of vitamin D in our body, we are unable to absorb calcium. Vitamin D also blocks, or inhibits, the release of parathyroid hormone which absorbs bone tissue.
Calcium is a mineral that is required to maintain bone health all through life, so ensuring our body can actually absorb this nutrient is an integral part our long-term health. Prolonged vitamin D deficiency can lead to brittle bones and increased risk of falls in the elderly.
There are new studies emerging that propose other beneficial functions of vitamin D in the body, but they are still in their early stages.
Where Do We Get It?
The most obvious (and free) source of Vitamin D is the sun. The sun’s UVB rays interact with a common cholesterol in our skin cells and a pre-vitamin D chemical. This reaction creates vitamin D3, which is then transported to the liver where it goes through a number of chemical changes before becoming the usable form of vitamin D.
Depending on skin tone, humans produce from 8, 000IU’s of vitamin to 50,000IU’s from just 30 minutes of exposure to midday sun.
For those of us living 37 degrees north or south of the equator, the amount of vitamin D we produce naturally decreases as we move into the winter months. The power of the sun’s rays change at different angles (zenith angle), so 30 minutes of midday, winter sun will not produce the same amount of vitamin D as midday, summer sun.
This is why we are often encouraged to consume a vitamin D3 supplement through the winter months. Research shows that the vitamin D we build up in the summer months is stockpiled, but these stores become depleted, which is why taking a supplement is recommended.
Vitamin D that we get in liquid or pill form is usually from the oils of fatty fish, or the wool of sheep. Don’t want to take a supplement form? Eggs and fatty fish are the only other substantial, natural sources of vitamin D out there besides the sun.
There are many fortified products on the market as well that have had vitamin D added to them. Vitamin D fortification for baby formula and cow’s milk is actually required by the canadian government.
How much do you need?
Dietitians of Canada recommend these doses of vitamin D to maintain the healthy function of the body.
- 1000 IU for infants 0-6 months
- 1500 IU for infants 7-12 months
- 2500 IU for children 1-3 years
- 3000 IU for children 4-8 years
- 4000 IU for children over 9 years of age and adults (including pregnant or lactating women)
In summary – we need to figure out our vitamin D strategy sooner rather than later. If we want to protect and maintain strength in our bones, it is imperative that we include adequate amounts of vitamin D in our diet this winter.
