Q. Can I take vitamins with food, or do I need to take them on an empty stomach?

Dorothy - About.com User

• Hydrochloric acid supplements work best when taken at the beginning of a meal. Hydrochloric acid supplements are often used by people who have trouble producing sufficient amounts of hydrochloric acid in their stomachs when they eat. If hydrochloric acid is taken on an empty stomach without the addition of food to digest, it will cause a warm to burning sensation in the stomach.
• Iron should be taken on an empty stomach for the best absorption. If you are taking just a bit of iron in a multivitamin it may not matter. If you are taking an iron supplement to treat anemia, it is best to take it on an empty stomach separately from other supplements, especially calcium and vitamin E.
• B Complex vitamins will often cause some mild nausea. This may be avoided by taking the B Complex vitamins with a light meal. A heavy greasy meal may interfere with absorption, so keep it light. The exceptions to this are B12 and folic acid which should be taken on an empty stomach.
• Proteolytic enzymes like bromelain may work best on an empty stomach. These enzymes digest proteins and they are often used in larger amount to help reduce inflammation. If taken with food, some of them may just end up being digestive enzymes.
• A lot of the bioflavonoids and phytochemicals are best absorbed on an empty stomach. Bioflavonoids and phytochemicals have several potential therapeutic benefits, and it is probably best to take them on an empty stomach for maximum benefit. Two examples are quercetin, and vinpocetine.
• Probiotics like acidophilus and lactobacillus should be taken on an empty stomach. These supplements are important for a healthy digestive system and are useful for treating Candida and for replenishing the intestinal flora after taking prescription antibiotics.