Drug-Nutrient Interactions

OMEPRAZOLE Also indexed as: Losec®, Prilosec®

Interactions with Nutritional Supplements

Folic acid Folic acid is needed by the body to utilize vitamin B12. Antacids, including Omeprazole, inhibit folic acid absorption. Those taking antacids are advised to supplement with folic acid.

Vitamin B12 Omeprazole interferes with the absorption of vitamin B12 from food (though not from supplements) in some studies. The fall in vitamin B12 status may result from the decrease in stomach acid required for vitamin B12 absorption from food, caused by the drug. However, all those taking Omeprazole need to either supplement with vitamin B12 or have their vitamin B12 status checked.

Ranitidine Also indexed as: Zantac®

Interactions with Nutritional Supplements

Folic acid Folic acid is needed by the body to utilize vitamin B12. Antacids, including ranitidine, inhibit folic acid absorption. Those taking antacids are advised to supplement with folic acid.

Iron Stomach acid may facilitate iron absorption. Ranitidine reduces stomach acid and is associated with decreased dietary iron absorption. Iron levels in the blood should be checked with lab tests.

Magnesium In healthy volunteers, a magnesium antacid, taken with ranitidine, decreased ranitidine absorption by 20%–25%. This interaction can be avoided by taking ranitidine two hours before or after any magnesium-containing antacids, including magnesium in vitamin/mineral supplements.

Vitamin B12 Stomach acid is needed to release vitamin B12 from food so it can be absorbed by the body. Ranitidine reduces stomach acid and is associated with decreased dietary vitamin B12 absorption. The vitamin B12 found in supplements is available to the body without the need for stomach acid. Lab tests can determine vitamin B12 levels.

Interactions with Other Compounds

Tobacco (Nicotiana species) A study of 18 healthy people found smoking decreased the acid blocking effects of Ranitidine.

© Vicki Martin, Nutrition and Herbal Technical Consultant, Healtheries of New Zealand Limited. Used with permission.