An analysis of data from the National Health and Nutrition Examination Survey (NHANES), among approximately 30,000 adults in the U.S., found that adequate daily intakes of vitamins A and K, magnesium, zinc, and copper from foods — but not from supplements — were associated with reduced risk of dying over a period of time. The study found that no vitamin or mineral supplement (including multivitamins) was associated with a decreased risk of death from cardiovascular disease or any cause after adjusting for factors such as age, gender, eating habits and lifestyle (Chen, Ann Intern Med 2019). Exceptions to the “foods are better” rule are two B vitamins. Ten to thirty percent of older people don’t properly digest and absorb natural vitamin B-12 from foods, so it is recommended to get B-12 from a supplement if you are over age 50. Folic acid (vitamin B-9) from supplements and fortified foods is absorbed better — about 70% better — than folate from regular foods such as spinach. Consequently, pregnant woman are advised to get folic acid from a supplement (or fortified food) as well as regular foods. Also keep in mind that if you get your iron from plant foods, it is absorbed only half as well as iron from meat — although eating your spinach (or iron supplement) with a source of vitamin C will boost the absorption of its iron.