The Importance of Vitamin D for your Health
Vitamin D is an essential vitamin for our bodies. The strength and growth of our bodies depends on it. The importance of vitamin D affects your entire body, and it is essential to make sure you get enough of it.
What Does Vitamin D Do?
Vitamin D has effects on the development, growth, and maintenance of a healthy body from conception on. Muscles need it to move, nerves need it to carry messages between the brain and different parts of the body, and the immune system needs it to fight off bacteria and viruses. Vitamin D is best known for its ability to stimulate the absorption of calcium which is critical for strong bones, a strong heart, and healthy muscles.
Deficiency in vitamin D can result in rickets in children and osteomalacia in adults. Both of these diseases are characterized by softening of the skull bones, bowing of legs, spinal curvature, and increased joint size although these diseases are very rare in developed countries. Recent studies are also linking low levels of vitamin D to thyroid disease and cancer, showing even greater importance of vitamin D for our health.
What is Vitamin D?
Vitamin D is a fat-soluble vitamin. However many experts consider vitamin D to be more of a hormone than a vitamin. This is because the human body was designed to receive vitamin D by producing it in response to just a few minutes of unprotected sunlight exposure, specifically UVB rays.
Where does Vitamin D Come From?
In addition to sun exposure, vitamin D is also available in supplements and certain foods. There are two types of vitamin D; vitamin D3 and vitamin D2, both of which must be converted in the liver and kidneys to the active form to be useful to the body. Vitamin D3, whether from supplements or food, is the same type made in the body in response to sun exposure. Studies have shown that vitamin D3 is the most readily used form of vitamin D in the body.
How much Vitamin D3 should I Take?
Vitamin D is measured in International Units (IU) and is potent in small quantities. Vitamin D3 supplements are typically from lanolin and cod liver oil extract and most effectively treat vitamin D deficiency. The recommended daily allowance for Vitamin D3 can vary slightly, depending on the organization making the recommendations. The Vitamin D Council recommends a minimum of 1,000 IU/day for children and 5,000 IU/day for adults, an amount that exceeds most multivitamins. Note for those over 71 years old, they recommend between 600 IU and 800 IU. The American Academy of Pediatrics (AAP) recommends 400 IU/day of vitamin D for infants, children, and adolescents.
How much Sun do I Need?
The importance of vitamin D in regards to adequate sun exposure, is it will typically provide upwards of 10,000 IU/day, so supplementation may not be necessary. It is also important to note that the amount of direct, unprotected sun exposure needed to produce adequate amounts of vitamin D usually happens within minutes, long before the skin begins to turn pink. So remember to protect your skin when you’re out in the sun!
Importance of Vitamin D in UVB Exposure
- Angle of the sun. If your shadow is longer than you are tall, you are not making much vitamin D.
- Time of day. Midday sun exposure between the hours of approximately 10am and 2pm is best for vitamin D production.
- Skin type. Vitamin D synthesis occurs faster in individuals with lighter skin types. Very light skin only needs around 15 minutes of sun exposure where those with dark skin will need exposure up to 6 times longer because darker skin allows less UV to enter the skin.
- Latitude. If you live in latitude from 0° to 35° north or south, year-round vitamin D production is possible. As the latitude increases, vitamin D production decreases.
- Amount of skin exposed. At least 40 percent of the entire skin surface should be exposed for optimal vitamin D production. The torso produces the most, legs and arms some, hands and face very little or none at all.
- Age. Individuals over the age of 60 and under the age of 20 can take up to four times as long to synthesize vitamin D.
- Sunscreen. Up to 95 percent of vitamin D production can be blocked by an SPF as low as eight.
- Altitude. More UVB is filtered out of the atmosphere at the beach as opposed to a mountain top.
- Being behind glass. Glass blocks all UVB rays.