Northerner
Admin (Retired)
- Relationship to Diabetes
- Type 1
A sometimes forgotten disadvantage of metformin is its effect on vitamin B12 absorption. Although the liability of metformin to lower vitamin B12 levels has been well described,[3] interest in the need for monitoring for vitamin B12 deficiency is more recent.[1,4-6]
Vitamin B12 deficiency is estimated to be present in up to 30% of patients with diabetes taking metformin.[1] The risk for vitamin B12 deficiency increases with patient age and the dose and duration of metformin use.[5,7] Concomitant conditions such as suboptimal dietary intake, which is common among vegetarians and alcohol abusers, and malabsorption due to atrophic gastritis, pernicious anemia, chronic pancreatitis, and celiac disease may further increase risk for vitamin B12 deficiency.[5] The combination of metformin with proton pump inhibitors has been reported to have an additive effect on risk for vitamin B12 deficiency.[8]
http://www.medscape.com/viewarticle/817601
(free registration required)
Vitamin B12 deficiency is estimated to be present in up to 30% of patients with diabetes taking metformin.[1] The risk for vitamin B12 deficiency increases with patient age and the dose and duration of metformin use.[5,7] Concomitant conditions such as suboptimal dietary intake, which is common among vegetarians and alcohol abusers, and malabsorption due to atrophic gastritis, pernicious anemia, chronic pancreatitis, and celiac disease may further increase risk for vitamin B12 deficiency.[5] The combination of metformin with proton pump inhibitors has been reported to have an additive effect on risk for vitamin B12 deficiency.[8]
http://www.medscape.com/viewarticle/817601
(free registration required)