In a clinical trial conducted by Oregon State University researchers, published in the journal Nutrients, older adults who took a daily multivitamin and mineral supplement with zinc and high levels of vitamin C experienced sickness for shorter periods of time, and with less severe symptoms, than their counterparts in a control group receiving a placebo. The trial lasted a total of 12 weeks, involving a total of 42 healthy people between the ages of 55 and 75, an age range associated with increased risk for micronutrient deficiencies.
 
Over the twelve-week period, illnesses were recorded via participant self-reporting – participants were instructed to provide researchers with incidences, severity, and length of any self-reported disease. On most days ill, 62% of the illnesses listed by the supplement users were very mild, whereas, 60% of the symptoms reported by the placebo group were mild or severe.
 
“This supports findings that stretch back decades, even to the days of Linus Pauling’s work with vitamin C,” corresponding author Adrian Gombart, professor of biochemistry and biophysics in the OSU College of Science, said. “Our results suggest more and better designed research studies are needed to explore the positive role multivitamin and mineral supplementation might play in bolstering the immune system of older adults.”
 
The study found that, compared to the placebo group, the multivitamin and mineral supplement users had increased serum levels of zinc, vitamin C, and vitamin D, all micronutrients associated with proper immune function. Despite this, a number of biomarkers pertaining to immune function that researchers evaluated remained unaltered, including neutrophil phagocytic activity, reactive oxygen species production, and white blood cells’ ability to kill incoming pathogens. Immune status markers which were measured included salivary IgA and plasma cytokine/chemokine levels.
 
Specifically, the supplement contained 700 mcg of vitamin A, 400 IU of vitamin D, 45 mg of vitamin E, 6.6 mg of vitamin B6, 400 mcg of folate, 9.6 mcg of vitamin B12, 1,000 mg of vitamin C, 5 mg of iron, 0.9 mg of copper, 10 mg of zinc, and 110 mcg of selenium.
 
While there was no significant difference between the two groups in terms of the frequency by which etiher group became sick, those who received a multivitamin supplement experienced fewer days of sickness, and their symptoms were less severe.  
 
“The observed illness differences were striking,” Gombart said. “While the study was limited to self-reported illness data and we did not design the study to answer this question, the observed differences suggest that additional larger studies designed for these outcomes are warranted – and, frankly, overdue.”
 
Research suggests that more than one third of older adults are deficient in at least one micronutrient, Gombart said.
 
“That likely contributes to a decline in the immune system, most often characterizerd by increased levels of inflammation, reduced innate immune function, and reduced T-cell function,” he said. “Since simple nutrients support immune function, older adults often benefit from multivitamin and mineral supplements. These are readily available, inexpensive, and generally regarded as safe.”