Vitamin D: The invisible deficiency that compromises overall health

Abstract

Vitamin D deficiency is one of the most common deficiency conditions worldwide, affecting millions of people in all age groups and in multiple clinical contexts. Despite its high prevalence, it continues to be underdiagnosed and undertreated, partly due to its silent course, the limited incorporation of screening into routine medical practice, and the persistent perception that its clinical consequences are limited to bone metabolism. This reductionist view has contributed to the underutilization of a safe, accessible therapeutic tool with broad preventive and prognostic potential in various chronic diseases.

For decades, vitamin D deficiency was mainly linked to rickets in children and osteomalacia in adults. However, advances in research have shown that vitamin D has receptors in multiple tissues, exerting endocrine, paracrine, and immunomodulatory functions that transcend its role in calcium and phosphorus homeostasis. It is now recognized that low levels of 25-hydroxyvitamin D are associated not only with bone fragility, falls, and fractures, but also with sarcopenia, muscle weakness, immune disorders, metabolic, neurocognitive, and emotional dysfunction, among other adverse outcomes.