Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.
The epidermis is the major source of vitamin D for the body. Under the influence of sunlight (ultraviolet radiation, action spectrum 280–320nM or UVB) 7-dehydrocholesterol in the epidermis is converted to vitamin D.
Vitamin D undergoes two hydroxylations in the body for activation. Calcitriol (1,25-dihydroxyvitamin D3), the active form of vitamin D, has a half-life of about 15 h, while calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days.
Symptoms of vitamin D deficiency may include:
Fatigue. Not sleeping well. Bone pain or achiness. Depression or feelings of sadness.
Vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and fractures (broken bones). Severe vitamin D deficiency can also lead to other diseases: In children, it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend.
Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
“Adding an over-the-counter vitamin D supplement can make improvements in just three to four months time. Vitamin D with a strength of 1000-2000 international units daily is the recommended dose for most adults,” Dr. Ropte says. Most multivitamins contain vitamin D, so extra supplementation isn't always necessary.
Abstract. To get an optimal vitamin D supplement from the sun at a minimal risk of getting cutaneous malignant melanoma (CMM), the best time of sun exposure is noon.
A common misconception is that you can get vitamin D from the sun through clothing. This is not true, as the only way to trigger the chemical reaction that results in vitamin D production is for sunlight to reach your skin directly.
Virtually all commercial and automobile glass blocks UVB rays. As a result, you will not be able to increase your vitamin D levels by sitting in front of a sunny window, though much of the UVA radiation will penetrate the glass and may be harmful.
The researchers took into account the amount of clothing and the season of the year. In spring and summer, 25 percent of the body (the hands, face, neck and arms) is exposed to the sun, and in these seasons, about 8 to 10 minutes of sun exposure at noon produces the recommended amount of vitamin D.
You need to have some skin exposed, for example, your forearms, hands and lower legs. But you can still make vitamin D even if you sit in the shade. Sitting inside by a sunny window doesn't count because glass filters out the UVB rays – the type of light that is needed to make vitamin D.
When we cover our skin with outer layers and/or sun screen, we are blocking the vitamin D producing sun rays. This essentially means we are preventing ourselves from ever producing our own vitamin D.
Use the CVS Health At Home Vitamin D Test Kit to get accurate and comprehensive results in the privacy and comfort of your own home. Simply collect your blood sample using this convenient kit, mail it to the lab, and receive your results through a secure online portal in just a few days.
Time of Day. The sun's rays vary in intensity throughout the day. In most places, UV rays are strongest between 10 a.m. and 4 p.m., when the sun is at its highest. If you go outside during that window, the body will produce more vitamin D in less time than if you went out in the morning or late afternoon.
"Adequate levels of magnesium in the body are essential for the absorption and metabolism not only of vitamin D but of calcium as well," Dean states. "Magnesium converts vitamin D into its active form so that it can help calcium absorption.
The concurrent presence of fat in the gut enhances vitamin D absorption, but some vitamin D is absorbed even without dietary fat.
Research also demonstrated that the higher the level of caffeine, the more it interfered with vitamin D absorption. The study suggested that caffeine did this by reducing the expression of vitamin D receptors on osteoblasts in the body – the cells responsible for producing bone.
[9,10] Low vitamin D leads to bone abnormalities (e.g., osteomalacia, osteopenia, and osteoporosis) and worsens muscle strength. [11] In otherwise healthy individuals, fatigue can be a manifestation of low vitamin D levels and its impact on reduced maximum functioning of skeletal muscles via vitamin D receptors.
Having inadequate levels of vitamin D may correlate with unintentional weight gain. A study on women over the age of 65 found that participants with a lower vitamin D level experienced more weight gain. A systematic review of 23 different studies found similar associations between vitamin D deficiency and obesity.
Vitamin D stimulates hair follicles to grow, and so when the body does not have enough, the hair may be affected. A vitamin D deficiency may also be linked to alopecia areata, an autoimmune condition that causes patchy hair loss.
According to the National Library of Medicine, vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and fractures (broken bones). Severe vitamin D deficiency can also lead to other diseases.