A July 2019 study found that only two out of 16 nutritional supplements tested had any positive impact. Researchers at West Virginia School of Medicine found that only folic acid and omega-3, long-chain fatty acids seemed to have some benefits.
The study found that, “…taking both calcium and vitamin may actually be harmful. The meta-analysis indicated--with moderate certainty--that taking a combination of calcium and vitamin D may increase the risk of stroke.
“But taking calcium or vitamin D alone seemed to have no effect on mortality or cardiovascular outcomes whatsoever. Neither did any of the other supplements that the meta-analysis addressed, such as multivitamins, iron, folic acid, beta-carotene and antioxidants.
“When the researchers turned their attention to diets, they discovered that eating less salt improved all-cause mortality rates in people with normal blood pressure. It also made cardiovascular-related deaths rarer among hypertensive people. But reducing sodium was the only diet that demonstrated any benefit. The other seven--which included eating less or different types of fat, adopting a Mediterranean diet and increasing fish-oil intake--had no effect.
Safi Khan said, "Reduced salt intake was associated with improving overall survival and cardiovascular mortality. This is something that can be backed up with logic because there is a sufficient amount of data, in various studies, that shows low salt intake basically improves hypertension, which directly influences cardiovascular outcome."