Vitamins can cause hives if you have an allergic reaction to one or more of the ingredients in the vitamin supplement. Some people can develop an allergic reaction to the vitamin itself, but is very rare. Anytime you take a new supplement or medication, there is an increased risk of having an allergic reaction. If hives develop after you take a vitamin supplement, call your doctor for further assessment. Hives are typically one of the first signs of an allergic reaction that can lead to a severe reaction called anaphylaxis.
While vitamin supplements help maintain your daily essential intake of vitamins and minerals, developing hives is an alarming symptom. You may be allergic to an inactive ingredient in the supplement, such as milk proteins or wheat proteins or you may be allergic to the vitamin. During the allergic reaction, a portion of the supplement is identified by the immune system as a dangerous substance, when it is in fact safe for consumption. The body creates immunoglobulin E antibodies that attack the allergen, according to MedlinePlus. These antibodies cause mast cells in soft tissue to produce histamine, a chemical that can lead to inflammation and swelling.
Hives are caused by the increased levels of histamine in the top layers of the skin. The increased histamine leads to irritation and inflammation, which triggers an outbreak of hives. Hives are itchy, red, raised, flat areas of the skin that develop in various shapes and sizes, according to the American Academy of Allergy, Asthma and Immunology. Most hives are the result of a food, medication or insect bite allergy. Hives that develop along with facial swelling, shortness of breath and lightheadedness are a sign of anaphylaxis. Anaphylaxis is an allergic reaction that affects the entire body and can lead to death if not treated.
Your doctor will recommend that you see an allergist to perform allergy tests to identify which substance is triggering the allergic reaction. A skin test uses a small amount of different substances and injects them under your skin. If you're allergic to one or more of the substances, your skin will become inflamed, red and swollen within 15 minutes. A blood test may be required to clinically diagnose your condition. During a blood test a sample of your blood is exposed to the suspected allergen to determine whether or not your blood creates IgE antibodies.
Hives from an allergic reaction are prevented by identifying the cause of the reaction and then eliminating that substance from your diet. If you develop hives, treat the rash with an antihistamine and topical steroid-based cream or lotion.