Vitamin D deficiency: Causes, Symptoms, Prevention and Treatment

Vitamin D deficiency

India is a vast Tropical country, with plenty of sunshine throughout the year. The human body can make its own vitamin D when exposed to sunlight unlike other vitamins. This vitamin is essential for overall good health and strong bones and also plays an important role in the functioning of your muscles, brain, lungs and heart and ensures that your body fights infection. This would make you believe that Vitamin D deficiency is uncommon in India.

So, you think you have adequate Vitamin D?

The results of a recent study are particularly alarming for health experts. The study revealed that a whopping 69 per cent of Indians suffer from vitamin D deficiency, while a further 15 per cent were found to be vitamin D insufficient.

Healthcare professionals blame fast-paced, stressed-out lifestyles. With long working hours and little or no time for outdoor activities, more and more people are suffering from vitamin D deficiency.

An estimated 1 billion people worldwide are Vitamin D deficient. It is relatively less common in western countries, due to the practice of fortifying milk with Vitamin D.

Why is Vitamin D so important?

Vitamin D is a part of the “Calcium-vitamin D-Parathyroid hormone” endocrine axis. It is crucial for calcium metabolism. Adequate calcium intake along with Vitamin D is necessary to maintain the peak bone mass achieved by an individual.                                                                                                                                 

Vitamin D adequacy during early age helps in reducing the risk of osteoporosis later in life. Deficiency of the vitamin and low calcium intake are important risk factors for osteoporosis. Deficiency can cause low bone mass, muscle weakness and therefore increased risk of fracture. Vitamin D deficiency and low calcium cause long standing secondary hyperparathyroidism leading to increased bone turnover causing osteoporotic fractures.

Who’s at risk?

Pregnant and breastfeeding women are more at risk of vitamin D deficiency, which is also prevalent in children between the ages of six months and five years, elderly people and those who aren’t exposed to adequate sunlight. Men between the ages of 30 and 60, adolescent girls and women between the ages of 15 and 30 are also likely to develop vitamin D deficiency.

What happens if I am Vitamin D deficient?

If you are Vitamin D deficient, then you have an increased risk of developing Rickets, osteomalacia and osteoporosis depending on your age group. The most well recognised function of active Vitamin D involves regulation of calcium and phosphorus balance for bone mineralization and remodelling. Without adequate levels in the bloodstream, dietary calcium cannot be absorbed. In the long term this leads to weakened and brittle bones that break easily. Approximately 40%–60% of total skeletal mass at maturity is accumulated during childhood and adolescence. Rickets results from inadequate mineralization of growing bone. Thus it is a childhood disease and it is manifested as bone deformities, bone pain and weakness.                                                                    

Chronic vitamin D deficiency in adults results in increased bone weakness, muscle weakness and increased risk of falls.                                                                            

Biochemical studies have implicated vitamin D deficiency in many chronic diseases including, but not limited to, infectious diseases, autoimmune diseases, cardiovascular diseases, diabetes and cancer.       

What would I feel if I am Vitamin deficient?

Bone pains, and muscle pains with easy fatiguability are the main symptoms of Vitamin D deficiency.

Why am I Vitamin D deficient?

You don’t consume the recommended levels of the vitamin over time. This is likely if you follow a strict vegetarian diet, because most of the natural sources are animal-based.

Your exposure to sunlight is limited. Because the body makes vitamin D when your skin is exposed to sunlight, you may be at risk of deficiency if you stay mostly indoors, wear long robes or head coverings for religious reasons, or have an occupation that prevents sun exposure.

You have dark skin. The pigment melanin reduces the skin’s ability to make vitamin D in response to sunlight exposure. Some studies show that older adults with darker skin are at high risk of vitamin D deficiency. This is the one of the important factors why this deficiency is so common despite adequate sunlight in Asian subcontinent.

For Indian skin tone, minimum “direct sun exposure” required daily is more than 45 min to bare face, arms and legs to sun’s UV rays (wavelength 290–310 nm). With the exception of those who perforce need to work outdoors in the sun, most Indians do not get adequate sun exposure to produce sufficient amounts of vitamin D endogenously.

Can a perfectly normal individual be deficient?

Studies from India show that Vitamin D deficiency has a very high prevalence rate upto 70-100%, even in otherwise healthy individuals of all age groups. All over India, vitamin D deficiency was highly prevalent in pregnant women and lactating mothers. Relatively, fish are a rich source of vitamin D. The residents of Bengal eat more fish compared to the rest of the Indians. Individuals of all walks of life are equally deficient, be it doctors, sportsmen, or even soldiers who eat well, exercise and spend good amount of time in the sun. Undoubtedly, the situation of Vitamin D deficiency is very grim in India, and has to be recognised as a major health problem.

How to prevent Vitamin D deficiency?

 It isn’t difficult to avoid this deficiency, though. Your body makes vitamin D when your skin is exposed to the ultraviolet rays of the sun. Fifteen minutes of daily sun exposure (without sunscreen) in the morning is recommended. This will help your body make vitamin D. Fatty fish such as salmon, fish oils, egg yolks, fortified milk and other fortified foods such as cereals etc. are also good sources of vitamin D.

Why is Vitamin D deficiency so common in India?

Vitamin D deficiency is a common problem in India due to several factors:

  1. Dietary sources of vitamin D have very low vitamin D content. Most of the food items rich in vitamin D are of animal origin. Commonly, a dietary source of vitamin D for vegetarians is milk, provided milk has been fortified with vitamin D. Milk is rarely fortified with vitamin D in India. The vitamin D content of unfortified milk is very low.
  2. Changing food habits contribute to low dietary calcium and vitamin D intake.
  3. Indian foods have a low calcium content. Most of Indians consume polished foods and pulses to whole seeds.
  4. High prevalence of lactose intolerance in India is a major deterrent pertaining milk consumption, further lowering intake of calcium and vitamin D in these individuals.
  5. High fibre diet containing phosphates and phytates which can deplete vitamin D stores and increase calcium requirement.
  6. Phytate is the principal storage form of phosphorus in many plant tissues, especially the bran portion of grains and other seeds. Phytate is indigestible to humans. Phytates chelate micronutrients such as calcium and iron, and thus reduce intestinal absorption of these nutrients.
  7. Most Indians consume milk as part of their tea or coffee. The proportion of milk is very low in these drinks. Thus calcium intake through these beverages is low. Vitamin D is stable during cooking. It is stable up to 200 °C. However, thermal stability of vitamin D is an inverse function of both temperature and time. In India, milk is boiled for several minutes before consumption. Before the same lot of milk is consumed in entirety, it is subjected to two-three rounds of boiling. In India most of the times, beverages like tea and coffee are boiled for several minutes to get the right flavour. This boiling may reduce the content of any vitamin D that there may have been left after boiling of the milk itself. Therefore, these beverages may not contribute significantly to either calcium or vitamin D intake in Indians.
  8. With modernisation, the number of hours spent indoor have increased thereby preventing adequate sun exposure. This is particularly true in the urban Indians.
  9. Increased pollution can hamper the ultraviolet rays to adequately synthesise vitamin D in the skin.
  10. Repeated and unplanned, un-spaced pregnancies in dietary deficient patients can aggravate Vitamin D deficiency in the mother and the foetus.

How to treat Vitamin D deficiency?

Let’s be clear about one thing- As Indians, we need more dietary intake of Vitamin d.

Fortification of food products is a simple and great solution to this problem. But it needs wider collaboration among government and food processing industry. Milk, milk products, infant formulas, wheat flour, Soy milk are widely consumed and can be fortified with Vitamin D to take care of the broader population. Unfortunately, we do not have too many products in India.

To treat vitamin D deficiency in children 2,000 IUs of vitamin D daily for 6–8 weeks, or 15,000 IUs per week is both effective and safe. In adults, 50,000 IUs of vitamin D once a week for 8 weeks (equivalent to approximately 6,500 IUs of vitamin D daily) is often adequate to treat vitamin D deficiency and replenish the Vitamin D stores. To maintain adequate levels of vitamin D subsequently, adults can take 50,000 IUs of vitamin D once every 2 weeks (equivalent to approximately 3,300 IUs of vitamin D daily) for at least 6 years without any concern for vitamin D toxicity.

The current recommendations of taking 1 to 1.5 gm of dietary calcium and 2000 IU of Vitamin D per day in the diet should be adhered to avoid Vitamin D deficiency in the Indian population.

Can I take Vitamin D supplements indefinitely?

No, excess of it can also be a big health problem. One must be careful not to over enthusiastically over treat without actually monitoring Vitamin D levels. Excessive ingestion of this vitamin may lead to increased blood calcium levels, constipation, decreased appetite, lethargy, dehydration, failure to gain weight in children, increased urination, increased thirst, nausea, vomiting, abdominal pain, deposition of calcium in kidneys, and headache.

Disclaimer- This is for the general awareness of the patients and cannot replace expert medical advice. The treatment of patient needs to be individualised based on clinical examination and evaluation by a trained physician.


I am a Neurosurgeon and spine surgeon practising in Gurugram, India. Besides Neurosurgery, I love to read, travel and play tennis.

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