PRECAUTIONS: Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain blood disorders (e.g., megaloblastic anemia, vitamin B12 deficiency), any allergies. This vitamin may be taken, as prescribed by your doctor, if you are pregnant or breast-feeding.

DRUG INTERACTIONS: Tell your doctor of all prescription and nonprescription medication you may use, especially: levodopa- containing products, pyrimethamine, hydantoins (e.g., phenytoin). Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include: stomach pain, vomiting, green-colored diarrhea.

NOTES: If your particular brand of vitamin also contains folic acid, your vitamin B12 levels may be checked periodically. Do not share this medication with others.

MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from light and moisture.

Report Problems to the Food and Drug Administration You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.