Association between Metformin, Vitamin B12 Supplements, and Vitamin B12 Deficiency in Type 2 Diabetic Adults: NHANES 1999-2006 Open Access

Abstract

Association between Metformin, Vitamin B12 Supplements, and Vitamin B12 Deficiency in Type 2
Diabetic Adults: NHANES 1999-2006
Context
Metformin is currently recommended as the primary treatment for diabetes and pre-
diabetes by the ADA. The association between metformin and vitamin B12 levels has been documented
but knowledge regarding the attenuation of this relationship by vitamin B12 supplements is lacking. This
information is especially important in older Americans who are at greater risk for both diabetes and
vitamin B12 deficiency.
Objectives
To describe the prevalence of metformin associated vitamin B12 deficiency among US
adults over 50 with type 2 diabetes and how this relationship is potentially modified by vitamin B12
supplements.
Design
Analysis of the nationally representative NHANES surveys from
1999-2006 of US adults over 50 who were either type 2 diabetic or non-diabetic (n=1621,6851). Population prevalence calculations were weighted according to
NHANES guidelines to represent the non-institutionalized US population over 50.
Main Outcome Measurements Serum B12 levels were classified as deficient at or below 148pmol/L and
borderline from 148 to 221 pmol/L.
Results Vitamin B12 deficiency was present in 5.5% of diabetics on metformin and in 2.1% of diabetics
not on metformin (p<.05). Borderline B12 deficiency was found in 12.8% of diabetics on metformin and
in 6.1% of diabetics not on metformin (p<.01). A stratified analysis based on B12 supplement use
indicated first, that taking B12 was protective against deficiency, and second, that for diabetics on
metformin, a minimum of 100 µgs of B12 should be taken daily. Metformin use was significantly
associated with serum B12 deficiency and borderline deficiency in a logistic model adjusted for age,
race, sex, and antacid use by odds ratios of 2.73 (95% CI 1.20-6.18) and 2.20 (95% CI 1.22-3.99)
respectively.
Conclusion
Metformin use puts US adults over 50 at a greater risk for vitamin B12 deficiency. This
risk is reduced by B12 supplement intake at levels of 100 micrograms per day or higher. Health care
providers should be aware of this relationship and serum B12 levels should by monitored annually in
diabetics taking metformin while the recommendation to take sufficient B12 supplements is made
evident.

Table of Contents

TABLE OF CONTENTS


Background ………………………………………………………..………….1
Abstract……………………………………………………..………………… 3
Introduction……………………………………………………………..……4
Methods………………………………………………………………………..6
Results………………………………………………………………………..… 9
Discussion………………………………………………………………………12
References…………………………………………………………………....15
Tables……………………………………………………………………………..17
Summary, Conclusions, Public Health Implications ………..47

About this Master's Thesis

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Rollins School of Public Health
Department	Epidemiology
Subfield / Discipline	Global Epidemiology - MPH & MSPH
Degree	MPH
Submission	Master's Thesis
Language	English
Research Field	Health Sciences, Public Health Health Sciences, Epidemiology
Keyword	Metformin Vitamin B12 Deficiency Diabetes NHANES
Committee Chair / Thesis Advisor	Oakley Jr., Godfrey, Emory University
Partnering Agencies	Emory University schools, faculty or affiliated programs

Last modified

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Association between Metformin, Vitamin B12 Supplements, and Vitamin B12 Deficiency in Type 2 Diabetic Adults: NHANES 1999-2006 ()	2018-08-28 14:28:08 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions