Vitamin D3 and Sunlight


Vitamin D is fat-soluble vitamin synthesized by the skin in the presence of adequate amounts of sunlight. It is also known as the “sunshine vitamin”. Since vitamin D can be easily synthesized by your body in sufficient quantities, it does not fall under the category of essential nutrients.

How vitamin D3 is formed

Vitamin D can be found in different forms. The main forms of vitamin D are vitamin D2/ Ergocalciferol and vitamin D3/ Cholecalciferol. When UV rays of sunlight fall on our skin, it initiates the process of production of vitamin D. Cholesterol in our skin is converted into vitamin D3 by the UV rays of sunlight. Therefore, it is safe to say that with enough sunlight, we do not need Vitamin D from food or supplementation.

Importance of Vitamin D3

Vitamin D3 plays an important role in the promotion of normal bone and teeth formation in babies. Its main function is to make calcium and phosphorus available in the body. Specifically, Vitamin D3 maintains calcium and phosphorus concentrations in the bloodstream by stimulating their absorption and mobilizing them from the bones to the blood. In addition, vitamin D3 is crucial for upholding the innate immune system of the body. It also contributes to preventing diseases like diabetes and cancer.

What happens in vitamin D3 deficiency?

The symptoms of Vitamin D3 deficiency correlates with that of calcium deficiency. The bone calcification process is disrupted making them so weak and fragile. As a result, they tend to bend, being unable to support the body weight.

A child with Vitamin D-deficiency may develop the disease called Rickets. This disease is characterized by soft and fragile bones, enlarged joints, bowed legs, and deformities in the chest, spine, and pelvis. In adults, this condition is known as Osteomalacia. Children who do not receive adequate sun exposure are more susceptible for Rickets.

Another disease caused by Vitamin D-deficiency is Tetany. It is characterized by low serum calcium levels of 7.5 mg/100 ml or less, muscle twitching, cramps, and convulsions. It is caused by insufficient calcium or vitamin D absorption, or from a malfunctioning parathyroid gland. This condition increases the risks of generalized seizures in infants.

Do babies need vitamin D supplementation?

Although a baby receives vitamin D3 through breast milk or formula milk, they contain only very small amounts. Since most of the time babies are kept indoors; they do not receive adequate exposure to sunlight which ensures sufficient vitamin D production. On the other hand, exposing a baby to direct sunlight has to be done with a lot of caution. Even when a baby starts to consume solid foods, it is at least not until 12 months of age, when he finally gets to eat whole eggs and dairy products which are rich in vitamin D.

As a result, it is recommended to give 400 IU (International Units) of liquid vitamin D daily to infants up to 12 months of age. After 12 months, when your baby gets to eat a wide variety of food items, receiving a vitamin D supplementation will not be necessary.

While providing a vitamin D supplementation to your baby you have to keep an eye on potential side effects of overdosing such as; nausea, vomiting, increased thirst, increased urination, and abdominal pain. It is believed that too much vitamin D3 can result in kidney damage as well.