Headaches can arise due to allergies, seasonal flu, stress and even hormonal changes. People who take prescription medications may develop a headache as a side effect of the medicine. Multivitamins and prenatal vitamins have side effects, and people taking them may experience stomach upset or headaches. In some cases, the headaches subside; however, some people may experience headaches as long as they take the supplement.
Side Effects
Some of the common side effects when taking multivitamins are upset stomach and unpleasant taste in the mouth. However, some people may also experience headaches while taking multivitamins. As the body becomes adjusted to taking multivitamins, these side effects may subside.
Overdose Symptoms
If you've taken more than the recommended daily allowance for your multivitamin supplements and are experiencing a severe headache along with hives, severe stomach pain, loss of appetite, nausea or vomiting, drowsiness, weakness, numbness and tingling in the fingers and toes or difficulty walking, seek emergency help immediately. These may be signs of vitamin toxicity or a severe allergic reaction to the vitamin supplement.
Consideration
If your multivitamin causes you to get headaches, contact your physician about changing your multivitamin. In some cases, this will be enough to eliminate the headaches. If you must take multivitamins to treat a vitamin deficiency, your physician may suggest taking a mild pain reliever until the headaches subside. He may also suggest that you take a different form of multivitamin, such as powder or liquid, or split the dose in half.
Safety
Do not take any medications along with your multivitamin without first consulting your physician. The Food and Drug Administration does not regulate multivitamin supplements, so they are not required to state an expiration or sell-by date. Expired multivitamins lose potency. Purchase only multivitamins that clearly state an expiration or sell-by date, and store them in a cool dry area.
