Fish oil has been particularly well studied in the context of cardiovascular health. Several vitamins like folic acid, vitamin D, and vitamin E have also been investigated, as have plant-based supplements like pycnogenol and high-nitrate beetroot juice. Red yeast rice can lower cholesterol, although any supplement with high levels of its active ingredient (lovastatin) cannot be sold legally in the United States. In contrast, some evidence suggests that calcium supplementation may negatively affect cardiovascular health.[1]