Micronutrients Support Upper Respiratory Health

A clinical trial published in October 2011 reports that micronutrient supplementation with vitamin C, vitamin D3, folic acid and selenium enhances upper respiratory health. Previous research indicates that these micronutrients support various aspects of immune function.

In this randomized, placebo-controlled, double-blind study, 192 subjects with suboptimal upper respiratory health consumed supplements with vitamin C, vitamin D3, folic acid and selenium or a placebo for 16 weeks. Researchers evaluated subjects for serum concentrations of the micronutrients and recorded upper respiratory issues.

The study authors found that in the participants with indications of suboptimal upper respiratory health, the subjects who received the micronutrient supplements reported enhanced upper respiratory health compared to the placebo group. Additionally, the subjects who initially reported several indications of suboptimal upper respiratory health also improved with micronutrient supplementation compared to the placebo group.

Of the subjects under age 45, fewer subjects were absent from their job during incidences of less than optimal upper respiratory health in the group receiving micronutrients compared to the placebo group. In fact, only 14.3 percent of subjects in the micronutrient group missed work while 47.8 percent of subjects missed work in the placebo group.

When taking a multinutrient, the subjects who had insufficient serum vitamin C or vitamin D prior to supplementation also experienced better upper respiratory health. Furthermore, micronutrient supplementation led to an increase in serum levels of vitamin C, folic acid and selenium after 16 weeks of supplementation. Serum vitamin D levels decreased in both groups, but decreased less in the group receiving the micronutrient supplement compared to the placebo group.

The researchers concluded that supplementation with vitamin C, vitamin D3, folic acid and selenium enhanced upper respiratory health in subjects susceptible to recurrent issues.

Reference:

Schmidt K, Zirkler S. Dietary efficacy of a micronutrient combination in patients with recurrent upper respiratory tract infections. Results of a placebo-controlled double-blind study. MMW Fortschr Med. 2011 Oct 6;153 Suppl 3:83-9.