Vitamin Information Center

Vitamin B12 (Cobalamin)
•Required for nerve function, synthesis of DNA and RNA, metabolism of energy,
enzyme reactions, and production of red blood cells.
•Used therapeutically for heart health (lowers homocysteine), male infertility, pre-
vention of neural tube defects, asthma, and cancer prevention.
•Defi ciency is common among the elderly and those with poor diets, pernicious ane-
mia, depression, Alzheimer’s, or malabsorption conditions (celiac disease).
•Defi ciency symptoms: anemia, appetite loss, constipation, numbness and tingling
in the extremities, and confusion. Pregnant women with defi ciency have increased
risk of giving birth to a child with neural tube defects.
•Drugs that deplete B12: acid-lowering drugs (omeprazole, lansoprazole, ranitidine),
oral contraceptives, antibiotics, cholestyramine, and metformin.
•Supplements are recommended for those over age 50, vegetarians, women planning
to become pregnant, those with poor diets, and those at risk of heart disease.

Vitamin B1 (Thiamine)
•Drugs that deplete vitamin B1: furosemide, antibiotics, oral contraceptives, and
phenytoin.
•Most people get adequate thiamine from diet and/or a multivitamin.Vitamin B1 (Thiamine)
•Required for energy production, nerve and muscle function, enzyme reactions, and
fatty acid production.
•Defi ciency causes beriberi, a disease that affects cardiovascular, nervous, muscular,
and gastrointestinal systems.
•Defi ciency is common in developing countries; in North America it occurs in alco-
holics, those with kidney disease, malabsorption syndromes (celiac disease), and
in those with poor diets.
•Drugs that deplete vitamin B1: furosemide, antibiotics, oral contraceptives, and
phenytoin.
•Most people get adequate thiamine from diet and/or a multivitamin