Which is better for you? Vitamin C or calcium supplements?
Axios / Reuters/Corbis / Getty Images – 2.5 out of 5 Vitamins and supplements have long been used as dietary supplements.
A 2010 review of the literature suggests that there is a strong correlation between vitamins and health benefits, and a 2016 meta-analysis of a dozen randomized controlled trials showed that the use of vitamin C in supplements was associated with lower risk of cardiovascular disease, Type 2 diabetes, and the common cold.
Some studies suggest that a vitamin C supplement reduces the risk of colon cancer and other types of cancer.
But the science remains mixed, and it remains unclear whether the benefits of a vitamin supplement outweigh the risks.
So far, no evidence exists that vitamin C can protect against cancer.
A 2015 review of nearly 200 randomized controlled studies found that the evidence supporting a causal link between vitamin C and cancer is not strong enough to support a causal relationship.
In fact, there is strong evidence that the risk from vitamin C exposure is higher than that from exposure to certain foods, according to a review of 15 randomized controlled clinical trials.
Vitamin C supplements have been shown to reduce the risk for several cancers, including prostate, breast, and colorectal cancer.
However, they do not reduce the risks for other cancers, and evidence suggests that the risks of some cancers are not due to vitamin C. Vitamin A, a fat-soluble vitamin that can be produced by animal and plant foods, also may reduce the cancer risk.
Researchers at the University of Washington found that vitamin A supplementation reduced the risk in a randomized clinical trial of people with type 2 diabetes.
Vitamin E, a fatty acid that is found in animal and vegetable fats, also appears to reduce cancer risk in some studies.
But other studies have found no benefit for vitamin E. In addition, a recent review of 12 trials that examined vitamin E supplements found that there was no evidence that vitamin E improved cancer outcomes.
Other research has also shown no benefit.
Researchers are still investigating whether vitamin E is useful for preventing or treating various types of cancers.
It is unclear if vitamin C supplements may reduce cancer, and there is no evidence to suggest that they can prevent cancer in any way.
You can learn more about vitamin C, calcium, and omega-3 fatty acids.