Nutrition and the upper respiratory tract

Abstract

On a population basis multiple nutrient deficiencies are common in developing countries, whereas in developed countries obesity and vitamin D deficiency are important health issues. While nutrient deficiencies can lead to disease, the results of clinical trials investigating the influence of supplementing various nutrients such as essential fatty acids, iron, and vitamin A on upper respiratory disease have been mixed. Probiotics may have a role in the treatment of upper respiratory disease, but appropriate probiotic strain/strains, supplement timing, as well as the dosage and method of administration continue to be debated. In clinical practice, many patients report that a milk exclusion diet is beneficial in reducing respiratory mucus production; however, the scientific basis for this remains controversial. Increasing evidence indicates that zinc supplementation is beneficial in the management of upper respiratory infections. A number of clinical trials also indicate that vitamin D supplementation has a potential role in the prevention of upper respiratory disease. Optimal vitamin D levels and dosages remain to be determined.