How some vitamin supplements increases stroke risk, by research

Vitamin supplements taken by millions of people can increase the risk of heart disease, a large study suggests.New research has found links between certain types of daily pills combining calcium and vitamin D and an increased risk of stroke.

United States (US) scientists believe the combination may be responsible for atherosclerosis, a disease whereby plaque builds up in the arteries.Such pills are commonly marketed as necessary to preserve bone strength and aimed at middle-aged and elderly people, whose risk of stroke is already higher.

Overall, it is estimated that around 45 per cent of adults worldwide take some form of vitamin supplements every day, supporting an industry worth roughly N1 trillion a year.Published in the Annals of Internal Medicine, the new data forms part of a wider set of results suggesting that few nutritional supplements protect against cardiovascular disease or death. Based on a review of 277 randomised controlled trials comprising nearly one million people, the study also questioned the effectiveness of a Mediterranean-style diet for improving resilience against heart disease.

Dr. Safi Khan, who led the research at West Virginia University, said: “A combination of calcium and vitamin D was associated with a higher risk of stroke.” He added: “Other supplements did not seem to have significant effect on mortality or cardiovascular outcomes.”

The research looked at the effect of 16 different nutritional supplements and eight dietary interventions on mortality and cardiovascular outcomes in the adult participants.

It concluded that cutting down on salt and eating omega-3 fatty acids, which are found in oily fish, offered some protection against heart disease, meanwhile folic acid offered some protection against stroke. Supplements combining calcium and vitamin D appeared to increase the risk of having a stroke by 17 per cent. However, scientists have urged caution in interpreting the results as establishing cause and effect is the field of nutrition is notoriously difficult.

“We found out only a few of the 16 nutritional supplements and one of the eight dietary interventions evaluated had some protective effect in cardiovascular risk reduction,” said Khan.Supplements that did not appear to have any significant effect on mortality or cardiovascular outcomes included selenium, vitamin A, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone, folic acid, and iron.