Many think that a supplement contains the same vitamins and minerals as whole foods, so why not just pop a pill? It’s because vitamins and minerals are best absorbed through food. Think of it like this whole foods contain a mix of minerals, enzymes, fiber, and other substances that may help your body absorb and use these nutrients. Eating a well-balanced meal is much healthier than a multivitamin. It’s not clear whether vitamins and minerals have the same effect in the body when taken in supplement form. If you have a true vitamin deficiency, however, a supplement may be helpful. Americans are most commonly deficient in vitamins D and B12, calcium, and iron. The only way to know whether you’re deficient is through blood work, but you might see some signs. If you’re experiencing symptoms you think a supplement could fix, consult your doctor before trying to remedy the problem yourself. Both vitamin E and the herb St. John’s wort can have dangerous interactions with blood-thinning drugs used to treat heart disease increasing your bleeding risk. Among people with heart disease being treated with the blood thinner warfarin, those most likely to experience bleeding events have higher levels of vitamin E in their bodies. Other studies have found that St. John’s wort amplifies the effect of blood thinners. Avoid these supplements if you’re taking a blood-thinning medication. Besides warfarin, those include apixaban, dabigatran, heparin, and rivaroxaban. Some people take niacin to raise HDL (“good”) cholesterol, but it can also affect your diabetes management. Niacin raises fasting glucose levels (your blood sugar levels when you are not eating) for people with diabetes, meaning the risks may outweigh the benefits. And while niacin can raise HDL cholesterol, there’s no evidence that this leads to a lower risk of cardiovascular disease. A chat with your health care provider can help you determine if this is safe for you to take.