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Vitamin D Requirements

What is Vitamin D?

This is a fat-soluble vitamin. Human skin has a high concentration of the sterol cholesterol which is converted by enzymes in the skin to the sterol 7-Dehydrocholesterol. When the skin is exposed to sunlight (ultraviolet B radiation), the 7-dehydrocholesterol is converted into vitamin D3. Vitamin D3 can be stored in the tissue for a long time.

Vitamin D Food Sources

Forms of Vitamin D

There are two forms of Vitamin D: Vitamin D2, and Vitamin D3.

Vitamin D2 is derived from fungi and plant sources (ergosterol). This is not produced by human body.

Vitamin D3 is made from animal sources when 7-dehydrocholesterol in the skin is exposed to ultra-violet light.

D3 is more effective than D2, therefore D3 is widely used as a nutrition supplement in United States.

Hindus and Vitamin D3 additives (supplements)

Health benefits

The vitamin D deficiency leads to rickets in children, and osteomalacia in adults.

Current meta analysis based on recent studies indicate that risk of Breast and Colorectal cancer is reduced by 50% with 1,000 IU of D3. Risk of ovarian cancer may be reduced by by 30%.

Daily Requirements

According to the IOM's report on the Dietary Reference

Ages 51-69: 400 IU

Age 70 and older: 600 IU

This requirement needs to increased by 50% due to melanin in South Asians.

Too much of Vitamin D can cause nausea, vomiting, poor appetite, constipation, weakness, and weight loss. It can raise blood levels of calcium, causing mental confusion and abnormal heart rhythm.

The Institute Of Medicine has set the following upper levels:

Infants to age 12 month: 1,000 IU

Adults: 2,000 IU

Vitamin D and South Asian Ageing