Vitamin D - The Sunshine Vitamin

Vitamin D

In recent times there is an alarming rise in Vitamin D deficiency with 2 in 3 Indians found to be deficient in Vitamin D. This article talks about this in detail. 

What is Vitamin D?

Vitamin D is known as the sunshine Vitamin. Vitamin D2 (present in our body through the food we eat) is converted by sunlight into Vitamin D3. This Vitamin D3 is converted by the liver and kidney into active Vitamin D that is useful for the body. The excess Vitamin D3 is stored by the body for later use. 

This active Vitamin D in turn helps in calcium and phosphorus absorption. Plant based foods have Vitamin D2 while only some animal based food has Vitamin D3 (liver, fatty fishes like salmon, mackerel, sardines), egg yolk.

Vitamin D is essential for healthy and strong bone growth and development in children.

Vitamin D guidelines

As per western guidelines, recommended level of Vitamin D are as follows:

Severe deficiency 

<5 ng/mL


<20 ng/mL


While majority of Indians live in areas receiving ample sunlight throughout the year, Vitamin D deficiency is still very common amongst all the age groups and both the sexes.

Below is a summary of some of the studies which conclude the same:

  • A 2018 study done on school going Indian children stated, though most of the children were exposed to sunlight for more than 2 hours still they had vitamin D Insufficiency. 
  • A school-based study on premenarchal girls of Pune in 2011. It showed a prevalence of 1 in 3 with Vitamin D deficiency. 
  •  Another school-based study in 2017 on 1222 school children aged 6–18 years in Kangra and Kullu districts of Himachal Pradesh, showed the prevalence of deficiency as high as 81% and 80% respectively.
  • Another study in the Nutrients Journal mentions more than 70% prevalence of Vitamin D deficiency among the Indian population.

Let’s understand what causes Vitamin D deficiency in spite of living in a sunny country?? 


  • Steep rise in low Vitamin D levels, all thanks to Covid restrictions. Increased indoor lifestyle leading to inadequate exposure to sun rays.
  • People with darker skin actually need more sunlight (as darker skin has lower sunlight absorption as compared to lighter skin). Many individuals want lighter skin and hence try and stay away from sunshine.
  • Pollution interferes with the formation of Vitamin D in the skin by UV rays.
  • Poor diet- A diet low in calcium and Vitamin D per se. 
  • Vegetarians are at a higher risk because of low Vitamin D availability in plant foods.

Vitamin D deficiency classification is as follows:

Severe deficiency 

<5 ng/mL


<20 ng/mL


Effect of deficiency:

In children it leads to,

  1. Rickets- soft, thin and brittle bones, bends in bone and other bone deformities.
  2. Osteomalacia- Bowing of the bones during growth period especially the weight bearing bones of the legs. 
  3. Delayed motor development
  4. Muscle weakness
  5. Aches and fractures

In adults it leads to,

  1. Osteomalacia - Softening of bones, pain in bones or weak bones and muscles. 
  2. Osteoporosis: Weakening of bones due to loss of bone density, thus frequent fractures. 

Eat a healthy diet and have an active lifestyle with healthy exposure to sunlight to increase your Vitamin D levels.