Vitamin D: Facts, Source, and Benefits


By: Ana Margarita Olar|

Vitamin D is not a vitamin but a steroid hormone that our body can produce. In total, there are 5 different forms of the Vitamins : D1 to D5. The most common are D3 and D2.


D3 also known as cholecalciferol is produced by the body. D3 is when the ultraviolet light (such as from the sun) converts cholesterol into calciol.

Then the liver converts it to calcidiol. The kidneys then convert this substance into a potent form of vitamin D which is calcitriol. However, this chain of reaction will not happen without ultraviolet light. So you need to be exposed to the sun in order for your skin to make produce vitamin D.

D2 also known as ergocalciferol is produced by fungi.

Vitamin d is a fat soluble hormone. It means that any portion not being used is stored in the body’s fatty tissue for future consumption.

A fair-skinned person who exposes the full body to the sun can produce up to 20,000 IU of vitamin D3 in 20 minutes.

Vitamin deficiency is common in infants, elderly and dark-skinned people because of the melanin in their skin which interferes with vitamin D production.

vitamin d


Own body through the help of sunlight- as mentioned earlier, sunlight is not the source of the vitamins. Rather, being exposed to the ultraviolet light of the sun facilitates production of vitamin D from the skin.

Oily fishes like salmon, mackerel, herring, swordfish, and sardine contain D3.

Shiitake mushrooms especially those that grown in full sunlight tend to have higher levels of vitamin D2.

Cod liver oil, canned sardines, canned tuna, eggs, fortified skimmed milk, and chicken.

Several studies have been done about the recommended supplemental dose of vitamin D. it ranges from 1000 to 4000 IU per day.

For pregnant, breastfeeding or elderly, the safe supplemental dose will be 600-800 IU.


  • It was first discovered as a substance that can prevent and cure
  • It controls a level of calcium and phosphate in the blood and with the absorption of magnesium and calcium in the intestines. Thus it plays a role in bone formation and the immune system. It also helps maintain strong bones and teeth.
  • Regulates insulin levels thus aids in managing diabetes
  • Supports respiratory and cardiovascular health.
  • Help in achieving healthy pregnancy because vitamin D lowers the risk of having preeclampsia
  • Reduces progression of cancer by slowing the growth and development of new blood vessels in the cancerous tissue thereby halting cancer cell growth and metastases.

Other recently studied benefits of vitamin D includes: it may reverse the progression of low-grade prostate tumors, it is beneficial for patients with multiple sclerosis, and it may also help patients with heart failure to improve their heart function.