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Function of Vitamin D

Kanika Khara Nov 20, 2018
Vitamin D is a fat-soluble vitamin that is synthesized by the human body on being exposed to sunlight. Here is a list of the functions of vitamin D.
Vitamin D, which is also referred to as the sunshine vitamin, is a fat-soluble vitamin that is found in two forms called ergocalciferol and cholecalciferol. Ergocalciferol, which is also referred to as vitamin D2, is mainly derived from plants.
On the other hand, cholecalciferol (Vitamin D3) is synthesized by the body when the skin is exposed to the ultraviolet rays of the sun. It must be noted that vitamin D that is obtained from food, dietary supplements, and sun exposure, is biologically inert.
In the body, some part of vitamin D is stored in the kidneys, liver, and bones, while the remaining helps in the absorption of calcium in the intestine. In the liver, the biologically inert vitamin D is converted into calcidiol. The kidneys change this vitamin into an active form called calcitriol.
The Recommended Dietary Allowance (RDA) of vitamin D for adults is 600 IU (15mcg). Since the body's ability to synthesize this vitamin decreases with old age, the RDA for those above the age of 70 years is 800 IU (20 mcg). The following sections provide information on the functions of vitamin D.

How does Vitamin D Benefit the Skin

Vitamin D has numerous benefits for our skin. It is used for the treatment of a skin condition called psoriasis, which is a chronic skin disease that is characterized by the development of dry, red patches that are covered with scales.
The easiest way to obtain vitamin D is to bask in the sun, so that the body can synthesize this vitamin from the ultraviolet rays that fall on the skin.

The ability to synthesize vitamin D from sun exposure decreases in case of the elderly. This applies to dark-skinned individuals as well. Hence, such people need to spend more time in the sun.
However, prolonged exposure to the sun could put one at an increased risk of developing skin cancer or premature aging. Thus, make sure that sun exposure is neither too less not too much.

What is the Function of Vitamin D in the Body?

Vitamin D helps the body absorb calcium. Together, vitamin D and calcium help strengthen the bones. It helps maintain normal calcium and phosphorus levels, which in turn helps maintain and build strong bones, teeth, and nails.
It also helps block the release of parathyroid hormone, which reabsorbs bone tissue, thereby making the bones brittle. Daily vitamin D supplementation has been shown to decrease the risk of falling in older individuals.
By controlling the supply of calcium between the bones and the blood, it supports bone mineralization (hardening of bones) and bone remodeling by osteoblasts and osteoclasts. Vitamin D also plays a substantial role in preventing rickets in children, and osteoporosis or osteomalacia in adults.
Also, it supports cell functions and other neuromuscular functions in the body. It also helps strengthen the immune system, which helps protect the body from infections and other illnesses.
Studies conducted at the University of Oxford and the New Jersey Medical School suggest that maintaining adequate levels of vitamin D could lower the risk of developing multiple sclerosis (MS).
Some studies suggest that vitamin D could help reduce the frequency and severity of symptoms in case of individuals affected by multiple sclerosis. Long-term research is required to substantiate these claims.
Vitamin D is believed to be a powerful antioxidant and anti-carcinogen. It is believed that it can help combat depression. Some studies suggest that it could lower the risk of prostate cancer, breast cancer, high blood pressure, cardiovascular diseases, etc. However, more research is required to corroborate these claims.
Some studies suggest that young individuals with higher vitamin D levels are at a lower risk of developing type 2 diabetes than those who had lower vitamin D levels. A few studies have shown that vitamin D supplementation could help alleviate some symptoms of type 2 diabetes.
Though long-term research is required to confirm the aforementioned effects of the sunshine vitamin, there's no denying the fact that it is essential for the overall growth and development of the body.

Sources of Vitamin D

Though the body synthesizes vitamin D from the UV rays of the sun, it is also found in food items like:
Cod liver oil
Egg yolk
Beef liver
Food items fortified with vitamin D (milk, yogurt, soy milk, orange juice, breakfast cereals)
Fortified foods are common sources of vitamin D. In fact, one cup of milk fortified with vitamin D provides almost half of the recommended daily intake for people who belong to the age group of 19-50 years.
Nowadays, many multivitamins, calcium, and vitamin D supplements are available. These can be used to maintain normal levels of vitamin D in the body, and alleviate the symptoms of its deficiency.
However, before taking any vitamin D supplement, do consult your healthcare provider regarding the right dosage. This is to avoid the untoward effects that could be associated with an overdose.
Disclaimer: The information provided in this item is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.