Raising vitamin D concentrations among hospital patients has the potential to greatly reduce the risk of hospital-acquired infections, according to a study published in Dermato-Endocrinology. Patients are often vitamin D deficient since many diseases such as cancer, cardiovascular disease, and respiratory infections are linked to low vitamin D concentrations.

Vitamin D plays an important antimicrobial role, the researchers wrote. Among the antimicrobial actions are reducing local and systemic inflammatory responses as a result of modulating cytokine responses and reducing Toll-like receptor activation and stimulating the expression of potent antimicrobial peptides, such as cathelicidin and β-defensin 2. Cathelicidins are a family of peptides thought to provide an innate defensive barrier against a variety of potential microbial pathogens, such as gram-positive and gram-negative bacteria, fungi, and mycobacteria, at multiple entry sites, including skin and mucosal linings of the respiratory and gastrointestinal systems, as well as some viruses.

One of the advantages of vitamin D in combating HAIs is that it strengthens the innate immune response, thus overcoming the antibiotic resistance of many bacteria encountered in hospitals, according to the authors.

Optimal vitamin D concentrations are at least 30-40 ng/ml (75-100 nmol/l). The average white American has a concentration of 26 ng/ml, while the average African-American has only 16 ng/ml. Vitamin D concentrations have fallen in the past 20 years, in part due to spending less time out-of-doors. About half of those admitted to hospitals have concentrations below 20 ng/ml, thus making them more susceptible to HAIs.
In an accompanying editorial, David McCarthy, MD, outlined what hospitals could do to overcome vitamin D deficiency among hospital patients. Among these recommendations is making high-dose vitamin D3 (5,000 and 50,000 IU) capsules available to the patients.