From the Research
Patients taking Ozempic (semaglutide) should consider vitamin B12 supplementation of 1,000-2,000 mcg daily or weekly, as this medication may reduce B12 absorption over time. Monitoring B12 levels annually is recommended, particularly for those on long-term treatment (beyond 1-2 years) 1. The risk of B12 deficiency occurs because semaglutide slows gastric emptying and may decrease intrinsic factor production, both essential for B12 absorption. Symptoms of deficiency include fatigue, tingling in hands and feet, memory problems, and anemia. Sublingual or oral B12 supplements are typically sufficient, though some patients with severe malabsorption may require B12 injections. Those at higher risk include vegetarians, vegans, older adults, and patients with prior gastric surgery or conditions affecting nutrient absorption. Regular consumption of B12-rich foods like meat, fish, eggs, and fortified cereals can also help maintain adequate levels alongside supplementation 2. It is also important to note that the use of medications like metformin for more than four months, use of proton pump inhibitors or histamine H2 blockers for more than 12 months, can also increase the risk of vitamin B12 deficiency 1. Therefore, patients taking Ozempic should be aware of these potential risks and take necessary precautions to maintain adequate vitamin B12 levels. In cases where vitamin B12 deficiency is suspected, measurement of serum methylmalonic acid should be used to confirm deficiency in asymptomatic high-risk patients with low-normal levels of vitamin B12 1, 3. Oral administration of high-dose vitamin B12 (1 to 2 mg daily) is as effective as intramuscular administration for correcting anemia and neurologic symptoms 1, 2. Intramuscular therapy leads to more rapid improvement and should be considered in patients with severe deficiency or severe neurologic symptoms. Absorption rates improve with supplementation; therefore, patients older than 50 years and vegans or strict vegetarians should consume foods fortified with vitamin B12 or take vitamin B12 supplements 1, 2. Patients who have had bariatric surgery should receive 1 mg of oral vitamin B12 per day indefinitely 1. Use of vitamin B12 in patients with elevated serum homocysteine levels and cardiovascular disease does not reduce the risk of myocardial infarction or stroke, or alter cognitive decline 1, 2.