Women and old people after the age of 60 years are prime candidates for Calcium supplements as they are considered vulnerable to bone related problems that include thin bones, brittle bones, frequent fractures, misshaped bones, osteomalacia and osteoporosis. Normally these supplements are supposed to deliver 500-800 mg Calcium per day. As Calcium is involved in formation and growth of bones, routinely these supplements are prescribed by orthopedists to many people and excess intake is not considered harmful hitherto. While high intake of Calcium is not known to be toxic, what other adverse effect it can have is a matter of conjecture with different reports indicating divergent views. Though a daily intake of 700 mg of Calcium is recommended for sound bone health, most of this requirement comes from every day foods like milk, cheese, yogurt, greens, leafy vegetables and fish with edible bones like sardines. It is believed that many older people do not get enough of this mineral increasing the risk of osteoporosis leading to thin and weak bones which can break easily, Same is true with women also at even younger ages due to hormonal changes during menopause. It is acknowledged that intake of Calcium supplements does increase bone strength but what is doubtful is whether it will really prevent fracture.
According to a recent review of some of the best scientific papers on Calcium in New Zealand, excess intake of this mineral can have other unintended consequences which calls for a re-look at the way Calcium supplements are prescribed in a routine way without realizing the long term consequences. Supplying Calcium over and above the intake through the food route can increase the risk of heart attack and strokes as increased levels of Calcium can affect the heart functions adversely, at least in some people. A study of 12000 people taking Calcium supplements, more than 500 mg per day regularly, has indicated that they faced a 30% increased chance of a heart attack during the period they took the supplement. Treatment of 1000 people with calcium supplements for a period of 5 years is estimated to cause 14 heart attacks, 10 strokes and 13 deaths but can prevent 26 fractures. also alarming is the finding that vulnerability to heart attack increased with higher dosage of Calcium supplement.Though the conclusion of the study is indeed alarming, a more careful analysis of the data indicates that out of the 12000 participants on Calcium supplement only 166 had heart attacks while 130 under the control and how significant this can be is uncertain. But qualitatively it does show the relevance or otherwise, of Calcium supplements in general, especially amongst those with even mild heart disease. As these studies were based on double-blinded controlled trials, there is no doubt about their reliability. Deciding on the risk-benefit aspects of Calcium supplements is indeed a tricky task. While bone fractures are not generally fatal, heart attacks can be and hence the dilemma for the health authorities in taking any decision.
One of the variables that has not been taken into consideration is about the complimentary effect of Vitamin D on the effect of Calcium intake as both of them are prescribed in most of the case because of the involvement of the former in bone development. Calciferol ( Vitamin D) is a critical vitamin formed under the skin from precursors already present in the body through exposure to Ultra Violet rays in the wave length range 270-300 nm and its bio-active form Calcitriol is known to reduce inflammation. Now that a shadow of doubt has been cast on the safety of Calcium supplements, it is necessary that these findings are validated through more thorough scientific studies to arrive at a reliable conclusion.