Am J Clin Nutr

Abstract

Background:Cognitive health is a public health concern among older adults. Dietary supplement (SUP) use is common and concerns have been raised about high folic acid intake among those with vitamin B-12 deficiency and exacerbation of poor cognitive performance (PCP).Objectives:We evaluated SUP use, usual folic acid intake, and blood folate and vitamin B-12 concentrations in relation to cognitive performance.Methods:We used NHANES 2011\u20132014 data on adults aged 6560 y (n = 2867) and estimated total usual folic acid intake from diet and supplements, vitamin B-12 intake from SUPs, blood folates, vitamin B-12 concentrations, vitamin B-12 insufficiency ( 64258 pmol/L), high folate (serum folate 6559 nmol/L or RBC folate 651609 nmol/L), and PCP (<34 on the Digit Symbol Substitution Test). We assessed folate distributions adjusted for multiple variables, including renal function.Results:Compared with persons without PCP, adults with PCP were less likely to use supplements containing folic acid (mean \ub1 SEE: 34.4% \ub1 2.4%) or vitamin B-12 (mean \ub1 SEE: 47.5% \ub1 1.6%). Among vitamin B-12\u2013insufficient adults, 18.0% \ub1 1.6% (mean \ub1 SEE) reported taking a vitamin B-12 supplement. Among participants with high folate and insufficient vitamin B-12 concentrations, 34.3% \ub1 11.5% (mean \ub1 SEE) reported taking vitamin B-12\u2013containing supplements. Persons with high folate and normal vitamin B-12 concentrations had lower odds of PCP [aOR (adjusted odds ratio): 0.61; 95% CI: 0.45, 0.83] than persons with normal folate and vitamin B-12. Persons with high folate and normal methylmalonic acid (MMA) had lower odds of PCP (OR: 0.56; 95% CI: 0.40, 0.78) than those with normal folate and MMA concentrations. After adjustment for renal function, elevated risk of PCP was attenuated among persons with high folate and MMA. Concurrent high folate and insufficient vitamin B-12 concentrations were not associated with PCP.Conclusions:Differential associations between vitamin B-12 and MMA highlight the need to consider renal function in studies of high folate and low vitamin B-12 status. Consumption of vitamin B-12 supplements concurrent with low vitamin B-12 status may indicate vitamin B-12 malabsorption. Am J Clin Nutr 2022;116:74\u201385.CC999999/ImCDC/Intramural CDC HHSUnited States