MANY INDIVIDUALS attribute their non- specific and unclassifiable health problems—like fatigue and body aches—to a minor vitamin deficiency that shows up on laboratory tests. Quite often, these symptoms are caused by lack of sleep, an unhealthy diet, lack of exercise or just plain mental stress, rather than a specific vitamin deficiency. However, anxious to ascribe a medical cause to their symptoms, and in their quest for perfect health, people often tend to overdose themselves with vitamins. Disturbingly, this is sometimes promoted by doctors and nutritionists too.
A typical example of this is vitamin D. This is a fat-soluble vitamin, essential for our bone and muscle health. Its primary role is to transport calcium from our intestines to the blood from where it reaches our bones. Dietary sources of vitamin D are negligible. We get our daily dose from the skin, where it is made under the influence of sunlight. Indians require longer exposure to the sun than Caucasians to make adequate amounts of vitamin D because their skin has more melanin pigment. Studies carried out over the last two decades have established that vitamin D deficiency is common in urban Indians, especially those with limited sunlight exposure. Several factors contribute to this. First, most Indians avoid the sun, for fear of skin darkening or just to avoid the heat. Second, even when they do go out in the sun, Indians do not expose much skin; the use of sunscreen lotions or creams which block UV rays also contributes to this. Third, atmospheric pollution prevents UV rays from reaching our skin. A study of Delhi schoolchildren showed that supervised sun exposure for 30 minutes daily for a month made little difference to their vitamin D levels.
Over the last few years, as recognition of this deficiency has grown, a surge in vitamin D testing has become evident. Except among those who complain of bone and muscle symptoms that can directly be attributed to this deficiency, there is really no need to order this rather expensive test. Levels of 25(OH)D, a measure of vitamin D in the body, above 20 ng/ ml or 50 nmol/L are considered sufficient. This is often accompanied by indiscriminate and excessive use of vitamin D supplements, which has resulted in an increasing number of cases of vitamin D toxicity. We reported our first such case series a couple of years ago in the journal Clinical Endocrinology—not with a sense of pride, though, as it reflects poor treatment practices in India. Unfortunately, our recent analysis suggests the phenomenon of man-made vitamin D toxicity is on the rise.
What leads patients and doctors to use excessive doses of vitamins? Perhaps it is driven by a desire to ‘fix’ things quickly; or maybe it results from ignorance on the part of the prescriber. It is quite common for patients to be advised injections of vitamin D, each containing 600,000 units to be taken weekly for up to six weeks. This is at least tenfold higher than the recommended doses, even for severe deficiency. Such large doses result in toxic levels of vitamin D in the blood, which lead to exceedingly high calcium levels. High calcium levels play havoc with our body, causing nausea, kidney failure, alteration in senses and, at times, even coma. Since it is stored in fat, vitamin D does not get washed out of the system for a few months, and many patients keep returning with recurring symptoms related to high calcium levels.
What then, is the right way to deal with this common deficiency? In reality, it is quite simple and cheap. We need to increase our sunlight exposure between 11 am and 3 pm, if possible. This may be difficult for many of us, though, and air pollution may spoil our plans. While food itself is a poor source of vitamin D, one could choose fortified food products. With the Government’s voluntary fortification strategy in place, the availability of vitamin D-fortified milk is getting better. Consumption of fortified milk (marked ‘F+’ ) can provide small quantities of vitamin D and reduce the deficiency’ s severity, although it may not be sufficient to completely rectify it. If you want to ensure that you are not deficient, the consumption of cheap supplements containing 1,000-2,000 units daily or 60,000 units once a month will ensure a safe correction of the vitamin D status of most adults. This can be implemented without having to resort to a blood test. It is especially recommended during winter months when sunlight fails to provide the requisite UV rays.
An immediate end has to be put to the use of excessive doses of vitamin D, as found in injectable preparations. As a physician who has been involved in vitamin D research for three decades, I am appalled at how such treatment schedules—which are not backed by research—have come into practice.