The study of 573 people found that those who took 500mg or more of vitamin C daily developed artery walls two and a half times thicker on average than those who did not take the supplement.
Physicians say that such thickening precedes atherosclerosis, or hardening of the arteries.
The head of the USC research team said that healthy people taking vitamin C supplements amounted to experimentation and that they should consider ceasing supplementation in light of the findings. Some nutritionists criticised the study. The weight of all published scientific evidence suggests that vitamin C is beneficial not only for the heart but also protects against cataracts and some types of cancer, said Annette Dickinson, of the Council for Responsible Nutrition. Other experts say that vitamin C is beneficial only when taken in its natural plant form and not by itself as a supplement. EMFs and suicide Exposure to electromagnetic fields increases the risk of committing suicide, US researchers have found.