Vitamin D deficiency is a global health problem. With all the medical advances of the century, vitamin D deficiency is still epidemic. Vitamin D deficiency prevails in epidemic proportions all over the Indian subcontinent, with a prevalence of 70%-100% in the general population. In India, widely consumed food items such as dairy products are rarely fortified with vitamin D. Indian socioreligious and cultural practices do not facilitate adequate sun exposure, thereby neglating potential benefits of plentiful sunshine. Consequently, subclinical vitamin D deficiency is highly prevalent in both urban and rural settings, and across all socioeconomic and geographic strata.

Vitamin D, also described as “the Sun Vitamin” is a steroid with hormone like activity. It regulates the functions of over 200 genes and is essential for growth and development. It’s a fat-soluble vitamin in a family of compounds that includes vitamins D-1, D-2, and D-3.

Your body produces vitamin D naturally when it’s directly exposed to sunlight. You can also get it through certain foods and supplements to ensure adequate levels of the vitamin in your blood.Body produces vitamin D naturally when it’s directly exposed to sunlight. You can also get it through certain foods and supplements to ensure adequate levels of the vitamin in your blood.

Vitamin D functions

  • Regulating the absorption of calcium and phosphorus
  • ​Facilitating normal immune system function to fight against diseases.
  • ​Helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy.
  • ​For normal growth and development of bones and teeth.
  • ​Improved resistance against certain diseases.
  • ​Boosts weight loss
  • ​Reduces depression.

Vitamin D Deficiency:

  • ​Rickets in children
  • ​Obesity
  • ​Diabetes
  • ​Hypertension
  • ​Depression
  • ​Fibromyalgia
  • ​Chronic fatigue syndrome
  • ​Osteoporosis
  • ​Neuro-degenerative diseases .

Its status depends on the production of vitamin D3 in the skin under the influence of ultraviolet radiation from sun and vitamin D intake through diet or vitamin D supplements. Usually 50 to 90% of vitamin D is produced by sunshine exposure of skin and the remainder comes from the diet. Natural diet, most human consume, contain little vitamin D.

What is RDA for Vitamin D:

COVID May go one day but what about Vitamin D Epidemic? Recommended Dietary Allowance for adults 19 years and older is 600 IU daily for men and women, and for adults >70 years it is 800 IU daily.

Range of vitamin D ( 25hydroxy vit D/ 25OHD)

​Normal -≥30 ng/mL.

​Insufficiency – 20–29 ng/mL

​Deficiency- ≤20 ng/mL

Exposure to sunshine each day helps human body to manufacture the required amount of vitamin D. However, due to fear of developing skin cancer most people avoid the sun exposure. To prevent vitamin D deficiency, one should spend 15 to 20 minutes daily in the sunshine with 40% of the skin surface exposed.

At Risk Population :

  • People who work indoors
  • ​Wear extensive clothing
  • ​Regularly use sunblock/ sunscreen
  • Those with IBD/ obese
  • Elderly or consciously avoid the sun
  • Pregnant or lactating women

According to one study carried out in Mumbai on Healthy adults total N = 214 Urban adults were observed, 81% M, 19% F, age 26–30 years.  87.5 were deficient in vitamin D.


Does vitamin D help the immune system?

Vitamin D3 is believed to play a role in controlling the immune system (possibly reducing one’s risk of cancers and autoimmune diseases), increasing neuromuscular function and improving mood, protecting the brain against toxic chemicals, and potentially reducing pain.

It can modulate the innate and adaptive immune responses. Deficiency in vitamin D is associated with increased autoimmunity as well as an increased susceptibility to infection. The immune system defends the body from foreign, invading organisms, promoting protective immunity while maintaining tolerance to self-defense.

Does Vitamin D levels and COVID has any correlation?

It has been established that people with low immunity & low levels of vitamin D are at High risk of COVID infection.

But yes a healthy vitamin D levels can enhance immune system & can build a good defence against respiratory infections;in general.


It plays an important role in modulating immune activity.Several studies point to an important role of vitamin D as an immunomodulator, & strong data demonstrate a role for 1,25(OH)2D3 in increasing the ability of the innate immune system to fight against pathogens, whereas data on the effect of 1,25(OH)2D3in the modulation of acquired immune system are more. Two key obeservtions validate this important non classical action: first vitamin D receptor (VDR) is expressed by majority of immune cells, including b & T lymphocytes,monocytes.Second, there is an active vitamin D metabolism by immune cells that is able to locally convert 25(OH)D₃ into 1,25(OH)₂D₃, its active form.

Summary of all; Vitamin D act as a nutrient,hormone & even as immunomodulator. It is very important to take RDA For all essential functions.Voll sante’s “Calgal XT” is best one for this,I strongly recommend this to all.

Dt. Mrs Shivani A Ingle

MSc. Food Nutrition & Dietetics

PGD in Clinical research, Certificate in Food & Nutrition, Diabetes Educator.

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