The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older Adults: A Double-Blind, Randomized, Controlled Trial

Abstract

Older adults are at increased risk for vitamin and mineral deficiencies that contribute to age-related immune system decline. Several lines of evidence suggest that taking a multi-vitamin and mineral supplement (MVM) could improve immune function in individuals 55 and older. To test this hypothesis, we provided healthy older adults with either an MVM supplement formulated to improve immune function (Redoxon^® VI, Singapore) or an identical, inactive placebo control to take daily for 12 weeks. Prior to and after treatment, we measured (1) their blood mineral and vitamin status (i.e., vitamin C, zinc and vitamin D); (2) immune function (i.e., whole blood bacterial killing activity, neutrophil phagocytic activity, and reactive oxygen species production); (3) immune status (salivary IgA and plasma cytokine/chemokine levels); and (4) self-reported health status. MVM supplementation improved vitamin C and zinc status in blood and self-reported health-status without altering measures of immune function or status or vitamin D levels, suggesting that healthy older adults may benefit from MVM supplementation. Further development of functional assays and larger study populations should improve detection of specific changes in immune function after supplementation in healthy older adults. Clinical Trials Registration: ClinicalTrials.gov #NCT02876315.

Keywords: illness; immune; multivitamin; placebo; randomized clinical trial; vitamin C; vitamin D; zinc.

Figure 1

CONSORT flow diagram of recruitment, allocation, follow-up and analysis.

Figure 2

The effect of MVM supplementation on circulating levels of vitamin C, zinc and vitamin D in placebo and Redoxon^® VI arm participants at baseline and 12 weeks post-supplementation. Compared with placebo, Redoxon^® VI increased (A) plasma vitamin C (p < 0.0001), (B) serum zinc (p < 0.0001), and (C) did not alter serum 25(OH) vitamin D concentrations (p = 0.15). The graph shows individual participant values in blue at baseline and red at 12 weeks; black horizontal lines show the median and interquartile range.

Figure 3

The effect of MVM supplementation on immune function in placebo and Redoxon^® VI arm participants at baseline and 12 weeks post-supplementation. Placebo and Redoxon^® VI participants did not differ in (A) whole blood S. aureus killing (p = 0.29), (B) neutrophil phagocytosis (p = 0.53) or (C) neutrophil ROS production (p = 0.13). The graph shows individual participant values in blue at baseline and red at 12 weeks; black horizontal lines show the median and interquartile range.