A German study has found that calcium supplements, commonly taken by older people to strengthen bones, may significantly increase the risk of heart attacks. Researchers at the German Cancer Research Centre in Heidelberg tracked nearly 24,000 people for over a decade, comparing heart attack rates among supplement users and non-users.
The study, published in the journal Heart, reported 851 heart attacks among the 15,959 participants who took no supplements. However, those taking calcium supplements were 86% more likely to have suffered a heart attack during the study period. The researchers advised that calcium supplements 'should be taken with caution'.
Dr Carrie Ruxton, from the Health Supplements Information Service, which is funded by supplement manufacturers, criticised the study, calling it a 'flawed survey'. She stressed that osteoporosis is a real issue for women and that the link between calcium, vitamin D, and bone health is endorsed by the European Food Safety Authority.
The British Heart Foundation (BHF) urged patients prescribed calcium supplements to continue their medication but to consult their doctor if concerned. Natasha Stewart, a senior cardiac nurse with the BHF, said the research indicates a possible increased risk but does not prove causation, adding that further research is needed to weigh risks against benefits.
Researchers from the University of Auckland in New Zealand, Ian Reid and Mark Bolland, argued that the evidence is growing that calcium supplements are neither safe nor effective. They recommended that people obtain calcium from a balanced diet rather than supplements, describing the latter as a 'low cost panacea' for postmenopausal bone loss.
A Department of Health spokeswoman stated that most people do not need calcium supplements, as a healthy balanced diet provides all necessary nutrients. Good sources include milk, dairy, fortified alternatives, and green leafy vegetables.
