Many health care providers recommend that you take a daily multivitamin to help maintain your health. Although taking a multivitamin in the morning is a great way to ensure that you don’t forget it, your morning cup of coffee could be interfering with the absorption of your vitamin's important nutrients, specifically iron. Certain substances in coffee can bind with iron and reduce absorption, so you don't get all the nutrients your body needs.
Iron is an important mineral that your body uses to make red blood cells. Your body regulates iron stores closely and tries to conserve and recycle iron. If your iron stores are low, your body will absorb more iron from food or supplements to help maintain proper levels. Iron is found in animal foods such as red meat and is also in plant foods such as beans or fortified cereals. Most over-the-counter multivitamins contain only a small amount of iron because men and women have very different iron needs.
Coffee -- when you consume it in moderation -- can provide several health benefits and may protect against Parkinson’s disease and Type 2 diabetes. Coffee is also very high in antioxidants, which may help prevent cancer. Coffee contains tannins, a type of polyphenol, a substance in plants that may interact with nutrients such as iron and decrease their absorption.
The tannins found in coffee can bind to the iron in food or a multivitamin and reduce absorption of iron by up to 50 percent. You may also drink your coffee with milk, and the calcium in milk further reduces iron absorption. Iron absorption can also be affected by your iron levels -- the lower the levels of iron in your blood, the more of the mineral that your body will absorb from foods.
If you are concerned about your iron levels, try to take your multivitamin or iron supplement later in the day -- at least two hours after you have consumed your morning coffee. Also include high-iron foods, such as lean red meat, beans or fortified cereals, in your diet. Consuming foods high in vitamin C can help with iron absorption, so include some strawberries, bell peppers or citrus fruits with your meals. One or two cups of coffee per day seem to be beneficial, but more can cause a fast heart rate or make you feel jittery, so try to keep your coffee intake moderate.
Ana Johnson is a registered dietitian with professional experience in clinical nutrition, weight loss and medical nutrition therapy. She has also covered nutrition for various online publications, including Smarty Pants Vitamins and HUM Nutrition. Johnson holds a Master of Science in clinical nutrition.