Most supplements should be taken with food to reduce the chances of causing stomach discomfort and to stimulate digestion and improve absorption. Eating a meal with healthy fats, such as lean meats, can increase vitamin C absorption by nearly 70 percent. Similarly, the body absorbs significantly more magnesium and zinc when ingested with food. Water-soluble vitamins, such as vitamin C and folate, should be taken on an empty stomach, while fat-soluble vitamins, such as vitamins A, E, D and K, should be taken with foods that contain fat for proper absorption.
Multivitamins or prenatal vitamins should also be taken with a snack or meal. It doesn't have to be a fat-containing meal. Vitamin A, which boosts vision and the immune system, is fat-soluble and should be taken with food. The best time to take prenatal vitamins may vary depending on your individual health factors, so talk to your doctor. The amount of compounds in most multivitamins makes it difficult to determine the best way to use these supplements.
For some people, it makes more sense to take these vitamins with a meal, such as lunch or dinner, but it's not necessarily necessary. Your skin produces “the sunshine vitamin” when exposed to sunlight, but it can be difficult to get enough from food sources alone.