Calcium today or brittle bones tomorrow. The choice is yours.” So goes an advertisement for a popular calcium supplement. Indeed, most over-the-counter calcium supplements in the market encourage consumers, especially 35-plus women who are increasingly at the risk of osteoporosis, to take these pills to save themselves from brittle bones, joint pains and a variety of other ailments.

What they fail to do, however, is to warn the consumer about the ill effects of taking calcium in excess of what they need. In fact, if a study conducted by researchers at New Zealand’s Aberdeen and Auckland Universities and published in the British Medical Journal last month is to be believed, then women should think twice before popping calcium pills mindlessly.

“The study claims that women taking calcium supplements to improve bone density face a 30 per cent higher risk of heart attacks if they have excess calcium in their bloodstream — a condition known as hypercalcaemia,” observed Ian Reid, one of the lead researchers of the study. Excess calcium usually gets deposited as plaque along the arteries, causing them to clog.

What concerns doctors and consumer experts is that none of the calcium supplements in the Indian market, whether they are in the form of tablets or energy drinks, carry information on their potential side effects. As consumer activist Bejon Misra points out, “It is the duty of the companies to mention on the labels of the products what can happen if someone takes calcium beyond the optimum level. Such over-the-counter products should carry specific instruction on who should have such tablets and in what dose.”

Calcutta-based orthopaedic surgeon, Dr Ronen Roy, explains, “Excess calcium in the blood stream is usually metabolised by the liver and kidneys, reducing the chances of hypercalcaemia. But if someone is flush with calcium and Vitamin D and their kidney and liver are not working properly or the person is predisposed to develop renal stones, then, he or she must be careful about taking calcium supplements.”

The popularity of calcium supplements, especially among women, is understandable because one in three women across the globe suffer from osteoporosis. “We advise women to start Sandoz calcium tablets from 35 onwards as after 45, when a woman reaches menopause, it is difficult to correct the calcium deficiency,” says a Novartis-Sandoz official.

Some firms insist that their products do carry all the information that the consumer needs to know. Prashant Pandey, general manager, Horlicks Megabrand, Glaxo Smithkline Consumer Healthcare, says, “Our brand, Women’s Horlicks, follows a complete list of micronutrients recommended by the World Health Organisation for women. The label mentions the presence of Hemocal Nutrients, which meets a woman’s daily requirement for calcium, protein as well as iron. Moreover, we specify how many spoons of the drink will give how much nutrient.”

Doctors also point out that a calcium supplement without Vitamin D added to it can be harmful. “Consumers should check if the supplement they are having contains the right combination of calcium and Vitamin D, as the latter is essential for the absorption of calcium. There is no point in popping calcium tablets that do not have Vitamin D,” says city-based physician Dr Kanchan Gurtu. “Though India is a tropical country (Vitamin D is synthesised by sunlight), most women are deficient in the vitamin, primarily because they avoid the sun and do not exercise,” he adds.

Again, even if some of these supplements contain a combination of calcium and Vitamin D, the nature of the Vitamin D may not be suitable.

“Most calcium supplements available in the market are rich in Calcitriol. But women should have a combination of calcium with Vitamin D in the form of Cholecalciferol. Otherwise, chances of hypercalceamia increases as excess calcitriol cannot be flushed out by the kidneys,” reveals Dr Roy.

That said, some doctors feel that chances of hypercalcaemia are not that high as most Indian women are calcium deficient. Says Dr Sushil Sharma, chairman, Arthritis Foundation of India, “A majority of Indian women are calcium as well as Vitamin D deficient. On an average, a healthy woman needs 1,000mg of calcium per day. But Indian women have a dietary intake of around 400-500mg of calcium a day (provided they have two glasses of milk, paneer and curd), making her deficient by almost 500mg. Her Vitamin D levels are also around four to 12 nanograms, though it should be around 30 nanograms.”

But can osteoporosis be prevented just by taking calcium supplements as claimed by manufacturers of calcium supplements? “Not really,” replies Dr Roy. “The female hormone oestrogen plays a role in keeping the balance between bone formation and bone leaching, thus maintaining blood calcium levels.” In pre-menopausal and menopausal women, the oestrogen level falls. There is an increased risk of osteoporosis as more and more calcium gets worn out from the bones to maintain the blood calcium level, leading to a fall in bone density.

Moreover, calcium alone cannot prevent osteoporosis. “Protein deficiency is also a major contributing factor,” says Dr Roy. “If a patient keeps on taking dietary supplements of calcium and Vitamin D, she may still be a victim of osteoporosis.”

So do take calcium supplements — but only if you need to. These over-the-counter products may promise you a rosy, osteoporosis-free future, but be sure to check out with a doctor your own individual requirement, if any, of calcium before you plump for them.