Omeprazole-Sodium Bicarbonate

In a study of elderly women, administration of omeprazole decreased the absorption of calcium, presumably because the drug decreased the stomach's production of hydrochloric acid, which is necessary for calcium absorption. The form of calcium used in the study to test calcium absorption was calcium carbonate. Drugs that reduce stomach acid secretion may not inhibit other forms of calcium, such as calcium citrate.

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

Treatment of healthy volunteers with omeprazole for four weeks resulted in a 12.3% decrease in blood levels of vitamin C.

In a study of nine healthy people, sodium bicarbonate administered with 10 mg of iron led to lower iron levels compared to iron administered alone. This interaction may be avoided by taking sodium bicarbonate-containing products two hours before or after iron-containing supplements.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Omeprazole interferes with the absorption of vitamin B12 from food (though not from supplements) in some but not all studies. A true deficiency state, resulting in vitamin B12-deficiency anemia, has only been reported in one case. 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. This problem may possibly be averted by drinking acidic juices when eating foods containing vitamin B12.

However, all people taking omeprazole need to either supplement with vitamin B12 or have their vitamin B12 status checked on a yearly basis. Even relatively small amounts of vitamin B12 such as 10–50 mcg per day, are likely to protect against drug induced vitamin depletion.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

People taking omeprazole may increase absorption of dietary vitamin B12 by drinking cranberry (Vaccinium marocarpon) juice or other acidic liquids with vitamin B12-containing foods.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

In a study of healthy human volunteers, supplementing with St. John's wort greatly decreased omeprazole blood levels by accelerating the metabolism of the drug. Use of St. John's wort may, therefore, interfere with the actions of omeprazole.

In a case report, a man developed severe magnesium deficiency after long-term treatment with a proton pump inhibitor (pantoprazole or lansoprazole). Severe magnesium deficiency as a result of the use of proton pump inhibitors appears to be rare among people who have no other risk factors for magnesium deficiency. However, in a study of hospitalized patients, the prevalence of low serum magnesium levels was significantly greater among users of proton pump inhibitors than among nonusers (23% vs. 11%). People taking proton pump inhibitors (PPIs) should ask their doctor whether to take a magnesium supplement or whether to have their magnesium levels monitored.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.