TAccording to a new study, taking calcium supplements can double the risk of cancer deaths.
Analysis of the medical records of 27,000 adults revealed links between high doses and cancer in recent years.
However, no link has been found between increased consumption of calcium-containing foods and illness.
Meanwhile, some other nutrients in foods – but not supplements – were generally associated with a lower risk of all-cause death and cancer.
Scientists writing in the Annals of Internal Medicine have stated that cancer patients may be at greater risk of danger by taking calcium supplement doses greater than 1,000 milligrams a day.
They found that after a follow-up of more than 12 years, there were approximately 24 cancer-related deaths per 1,000 person-years, compared to 12 non-users.
In the UK, nearly 5 million people take calcium and vitamin D supplements in order to avoid osteoporosis at a later age.
The scientist in charge, Dr. Fang Fang Zhang, of Tufts University, said: "It is important to understand the role that the nutrient and its source could play in health outcomes, especially if the effect is not beneficial.
"Our results support the idea that, while the use of supplements contributes to an increase in total nutrient intake, there are beneficial associations with nutrients from foods that we do not see with the supplements.