From the FDA Drug Label
- 1 Drugs Dependent on Gastric pH for Absorption Famotidine can reduce the absorption of other drugs, due to its effect on reducing intragastric acidity, leading to loss of efficacy of the concomitant drug.
The FDA drug label does not answer the question.
From the Research
Famotidine generally does not significantly interfere with vitamin absorption, but long-term use may have a minor effect on the absorption of vitamins that require an acidic environment, such as vitamin B12, iron, and calcium. The mechanism of action of famotidine, an H2 blocker, reduces stomach acid production to treat conditions like heartburn and acid reflux, which is different from proton pump inhibitors (PPIs) that can affect absorption of certain nutrients with long-term use 1. However, any medication that reduces stomach acid may theoretically have some minor effect on the absorption of vitamins that require an acidic environment. If you're taking famotidine regularly for an extended period, it's reasonable to maintain a balanced diet rich in essential nutrients or consider a multivitamin supplement, as some studies suggest that deficiencies in vitamins A, D, E, and K can be caused by digestive tract disorders or impaired absorption 2. Most patients taking standard doses of famotidine (20-40 mg daily) for common indications like GERD or peptic ulcers don't need to worry about vitamin deficiencies, as any potential effects are minimal compared to the medication's therapeutic benefits, and the clinical evidence confirms that famotidine is very well tolerated and is free of the antiandrogenic effects infrequently reported with cimetidine 3. Some studies also suggest that vitamin B12 deficiency can be caused by inadequate intake, inadequate bioavailability, or malabsorption, and that the absorption of levothyroxine can be affected by various factors, including gastrointestinal disorders and certain medications 4, 1. In general, the potential effects of famotidine on vitamin absorption are minimal, and the benefits of taking the medication for its intended purpose outweigh the risks of vitamin deficiency. It's essential to note that the majority of the interactions between medications and vitamin absorption are clinically significant and can be avoided by separating the administration of the medications and the interfering substances 1. Overall, while famotidine may have a minor effect on vitamin absorption, the benefits of taking the medication for its intended purpose outweigh the risks, and patients can minimize the risk of vitamin deficiency by maintaining a balanced diet and considering a multivitamin supplement if necessary.