Multivitamins are a dietary supplement that contains different vitamins in one pill. Most multivitamins are synthetic, making it possible to take one pill daily. Every brand of multivitamins contains various ingredients and different amounts of each vitamin and mineral. Before using a multivitamin, read the allergen warnings and talk with your doctor. Certain conditions may limit the type of multivitamins you may be able to take safely. Stomach pain is a common side effect of taking multivitamins, but may be a sign of a more serious condition. Discuss any adverse reactions you develop after taking a multivitamin.
Common Side Effects
Multivitamins are commonly used to provide the essential vitamins and minerals that are found in foods to maintain your health. You may be prescribed specific multivitamins if you are pregnant or have a disease that leads to vitamin deficiencies. Drugs.com states that it is common for you to develop an upset stomach, headache or an unusual taste in your mouth after taking a multivitamin. If you have a sensitive stomach or you're taking the vitamin on an empty stomach, you're more likely to develop unwanted side effects, such as stomach pain and discomfort.
Vitamin Allergy
Any substance that you ingest can cause an allergic reaction. Because most multivitamins are synthetic in chemical composition, you may have an allergy to the synthetic vitamin and not to the vitamin naturally occurring in foods. Tree.com states that vitamin allergies are uncommon but may cause hives, an upset stomach, diarrhea, nausea, vomiting, skin rashes, asthma and nasal congestion. The reaction is the result of a hypersensitivity of your immune system to one or more of the vitamins in the supplement. The overreaction of the immune system causes the release of immunoglobulin E antibodies and histamine, two chemicals that cause inflammation, according to the American Academy of Allergy, Asthma and Immunology.
Food Allergy
Some multivitamins may contain allergic food byproducts, such as wheat, soy, milk or eggs. If the product contains any high allergic food ingredients, the manufacturer is required by law to place an allergen warning on the bottle and the packaging. If you have a known food allergy, talk with your doctor before taking a new multivitamin.
Other Ingredients
Other conditions, such as irritable bowel syndrome, Crohn's disease and celiac disease, may contribute to stomach pain from taking a multivitamin. For example, if the supplement contains gluten and you have celiac disease, you can experience severe stomach pain, diarrhea and vomiting.
