Question: does omeprazole cause vitamin deficiency?
Answer: Popular Antacids Could Cause Vitamin Deficiency. Medications like Prilosec and Nexium could give patients a Vitamin B12 deficiency if they're taken for more than two years, a new study shows. People taking acid-inhibiting medications, such as Prilosec, Zantac, Pepcid, or Nexium, could be short on Vitamin B12.