Vitamin D: Most scientists now agree that the vast majority of vitamins and mineral supplements are at best wasteful. Vitamins A, C, and E in supplement form are actually detrimental to health. But D supplements are an exception. Studies suggest they reduce kids’ chances of catching the flu, improve bone health, and even prolong life.
Zinc: Vitamin C tablets won’t help fight a cold, but zinc lozenges do. Zinc reduces both the symptoms and duration of the ailment.
Niacin: Niacin, or B3, supplements appear to reduce the chance of heart attack or stroke among people with heart disease. Prescription-level doses might help with a range of other conditions, including diabetes, headaches, and Alzheimer’s.
Garlic: Concentrated garlic in supplement form has been shown to be an effective treatment for high blood pressure.
Source: SmithsonianMag.com