Abstract
Purpose:
Metformin is a common medication for patients with hyperglycemia. In adults, one well-documented side effect of metformin is vitamin B12 deficiency. This side effect, however, has rarely been studied in pediatric patients. This study examined the changes of vitamin B12 levels in pediatric patients being treated with metformin administration.
Methods:
Data from pediatric patients (n=151) with at least 3 months of consecutive metformin intake were collected. The effects of varying doses of metformin on the mean vitamin B12 level were investigated at 6-month, 12-month, 24-month and 36-month intervals. The degree of compliance of metformin intake on vitamin B12 level also was studied.
Results:
There was no significant decrease in mean vitamin B12 levels in patients treated with metformin at 6-month, 12-month, 24-month, and 36-month intervals. Mean vitamin B12 drop was only noticeable (p<0.05) in patients taking high dose of metformin with a good compliance. Despite this drop, the mean vitamin B12 remained well within the normal reference range. Furthermore, of the 151 patients studied, only one patient demonstrated vitamin B12 deficiency after 12 months of treatment. However, his B12 level returned to normal at the 24-month and 36-month intervals without any vitamin B12 supplements. Our findings suggest metformin treatment in children does not cause vitamin B12 deficiency; however, long-term treatment could reduce vitamin B12 levels when patients take a high dose consistently.
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