Adverse effects of Vitamin D deficiency

Recent studies have revealed that more than 80 per cent people in India suffer from Vitamin D deficiency. S Nandita, an ex-brand manager and a freelance writer, gives an idea about the cascading effects of it and how it can be overcome

Be it technology, economy or research, India is shining, but is it really? India is located between 8.4 and 37.61N latitude, which ensures seven hours of sunshine during the summer months and three to four hours during winters and is known as the sunny country. Despite having plenty of sunshine, Vitamin D deficiency is widely prevalent here. Vitamin D is produced from cholesterol when the skin is exposed to sunlight.

However, recent studies have estimated that more than 80 per cent Indians have low 25 (OH) D levels and Vitamin D deficiency is prevalent in most parts of the country, irrespective of people's age, socio-economic conditions and education status1.

In rural areas, Vitamin D levels are better due to exposure to sun but dietary calcium levels are poor, whereas in urban areas dietary calcium is better but there is a deficiency of Vitamin D because a majority of people are working from dawn to dusk in air conditioned offices and even during outdoor excursions, pollution laden clouds and the use of sunscreens limit their exposure to the sun.

Other contributing factors are consumption of foods rich in phytates such as chapattis and legumes and less outdoor activity. Genetics and skin tone also have a role to play in Vitamin D absorption too. Presence of increased 25 (OH)D- 24 - hydroxylase degrades 25 (OH ) D to inactive metabolises2. In addition, social and religious customs that require people to wear concealing clothing, veils and traditional attire, such as the burqa, salvar kameez significantly prevents exposure to sun rays.

The large pool of data gathered from across India demonstrates that Vitamin D deficiency is not restricted to the elderly or to the confined but can strike individuals in the prime of their life and affect the quality of life and the productivity 3,4.

When it comes to bone health, Vitamin D and calcium go hand in hand. In the early stage of Vitamin D deficiency, human body adapts by increasing the parathyroid hormone in the blood, which helps in maintaining the normal calcium levels and, hence, the deficiency is not easily detectable. But in the long run, Vitamin D deficit leads to bone resorption, a condition where the bone breaks down to release of calcium in the blood. Vitamin D deficiency leads to lowered absorption of calcium thereby leading to brittle bones, osteomalacia, rickets and persistent non-specific muscular pain and speedy onset of osteoporosis and osteoarthritis. It has always been known that Vitamin D is required for healthy bones. Over 90 per cent of fractures occur after a fall and fall rates increase with age and poor muscle strength or function. Thus, the benefit of Vitamin D on both fall and fracture prevention is of significant clinical importance. However, this is just the tip of the iceberg. Vitamin D receptor is expressed in more than 30 tissues and has a crucial role to play in transcription of several genes.

Vitamin D deficiency has also been shown to lead to immune disorders and may be the precursor to malignancy. It is also said to play a role in wheezing disorders, multiple sclerosis and mental problems.

It has been proven that a daily intake of 1200 mg of calcium and 800 IU of Vitamin D can reduce the risk of diabetes. It improves insulin secretion and production by the B-cells of pancreas and also affects secretion by increasing the intracellular calcium concentration.

Increasing evidence points that it reduces the risk of heart disease by modulating the heart's muscle shape and function. Vitamin D deficiency increases blood vessel contraction and hypertension, as well as causes inflammation in arteries leading to blockages.

A study conducted in 2006 mentions that Vitamin D deficiency was common in Indian school children and when remedied medically, it led to significant increment in height, bone mineral density and weight.

Vitamin D-rich diets include liver, eggs, oily fish, and fortified food, which is not so far prevalent in India. Another study conducted in November 2011 has reported Vitamin D deficiency in healthy Indians above 50 years in northern part of the country5.

Another study has reported requirement of 60,000 to 1,20,000 IU per month to achieve Vitamin D level > 30 ng/ml; the level is considered to be sufficient.

When the crisis is so widespread and a cascade of problems has been predicted, it is time for the government to 'see the light' and take drastic measures. As in countries like the US, Vitamin D fortification should be undertaken on a large scale, on the lines of salt iodinisation.

Opportunity for the pharma industry

Vitamin D has important implications in the therapeutic aspects of disease processes. Vitamin D supplementation may be the route to defeat not only bone problems but a host of other anomalies. While food fortification is one way, supplementation, whenever necessary, is definitely called for. This opens up a great new opportunity for the pharma industry too.

The vitamins, minerals market is increasingly throwing up these new opportunities.

From a generalised supplementation for debility, condition specific uses are emerging. And with prevention becoming as important as treatment, the industry is certainly looking forward to it.

References:
1. J Assoc Physicians India 2009;57:40-48.
2. Clin Endocrinol Metab 1998;83: 169-173.
3. Indian J Med Res 2008;127:239-244.
4. Osteoporos Int 2005;16:397-402.
5. J Assoc Physicians India 2011;59: 703-707.