Vitamin D Deficiency and Health Risks?


Dr. Shalini Mukherjee, Ph.D

Vitamin D Deficiency and Health Risks? 

If vitamin D is made by our own body when exposed to sunlight, why then the widespread deficiency among vast segments of the population?

Make D while the Sun Shines: Vitamin ‘D’ is one of the few that are synthesized by our body itself. Thirteen minutes in the summer noon sun about three times a week is enough for a Caucasian adult in UK to get sufficient amount of Vitamin D (1). But further up north in Norway, the same person will need three or four half-hour exposures a week for the same result (2).

But this is only the sunny side of the story. The sad part is, the UV-B, which is at its peak around noon, is known to cause skin cancer. In India, an adult needs at least one-hour of exposure in the sun between 11 am- 3 pm, taking into account factors like clothing and sunscreen lotions (3). But this is w.r.t casual sunlight exposure. In a tropical country like India, the natural tendency is to avoid exposure to the scorching midday sun. An urban adult is therefore hardly exposed to adequate sunlight required for subcutaneous Vitamin D synthesis.

Therefore the necessity to compensate for the requisite amount of Vitamin D through food. Most of the foods rich in Vitamin D are ‘non-vegetarian.’ Due to dietary habits, people in Western countries are easily able to substitute subcutaneous synthesis through sufficient in-take of fish (Cod, Salmon, Swordfish, Tuna), meat and eggs.

However in India, due to cultural reasons and otherwise, vegetarian diet remains the preferred choice for a large part of the population. Therefore all the more the need for supplements and fortified food. The vegetarian diet needs to be heavy on milk, yogurt, cereals and juices fortified with vitamin D to balance the absence of meat and eggs.

But why do we need vitamin D? This vitamin is essential for certain metabolic processes namely calcium, phosphate and bone metabolism. These physiological processes show their outcomes not only in the apparent musculoskeletal fitness of a person, but also in their cardiac health and the ability to fight various kinds of cancer.

Vitamin D is also one of the most vital supplements for a pregnant or lactating woman, as the requirement in infants cannot be fulfilled by breast milk alone (4).  A severe deficiency of the D could also result in termination of pregnancy.

The question that comes to our mind, therefore: If vitamin D is made by our own body under sunlight, why then the widespread deficiency among vast segments of the population?

Community and hospital-based studies in India show deficiency of the sunshine vitamin is rampant amongst all age groups in both sexes (5).  The answer lies in the lack of awareness.

Awareness through understanding and sharing of knowledge will help spread the word: “Make vitamin D while the sun shines.”  Choose your diet wisely comprising well-balanced foods to obtain the daily dose of all the important elements in order to live a healthy life.

Dr. Shalini Mukherjee, Ph.D (Molecular Biology), University of Manitoba, Winnipeg, Manitoba, Canada.

September 12, 2019


1. Rhodes LE1, Webb AR, Fraser HI, Kift R, Durkin MT, Allan D, O’Brien SJ, Vail A, Berry JL. Recommended summer sunlight exposure levels can produce sufficient (> or =20 ng ml(-1)) but not the proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels at UK latitudes. J Invest Dermatol. 2010 May;130(5):1411-8. doi: 10.1038/jid.2009.417. Epub 2010 Jan 14.

2. Cicarma E1, Porojnicu AC, Lagunova Z, Dahlback A, Juzeniene A, Moan J. Sun and sun beds: inducers of vitamin D and skin cancer. Anticancer Res. 2009 Sep;29(9):3495-500.

3. Vivek G Patwardhan, Zulf M Mughal, Shashi A Chiplonkar, Ann R Webb, Richard Kift, Vaman V Khadilkar, Raja Padidela, Anuradha V Khadilkar. Duration of casual sunlight exposure necessary for adequate Vitamin D status in Indian Men. Year: 2018  Volume: 22 Issue: 2 Page: 249-255.

4. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.

5. Aparna P, Muthathal S, Baridalyne Nongkynrih, and Sanjeev Kumar Gupta. Vitamin D deficiency in India. J Family Med Prim Care. 2018 Mar-Apr; 7(2): 324–330. doi: 10.4103/jfmpc.jfmpc_78_18.