Vitamin D and Primary Immunodeficiencies

Some of the recognized actions of vitamin D include immunological effects such as keeping tolerance and to promote protective immunity. These functions are related to the blocking of B cell differentiation and immunoglobulin secretion as well as decreased production of inflammatory cytokines. The aim of this study was to describe the frequency of vitamin D deficiency in patients with primary immunodeficiencies. We studied 31 patients: 14 with Ataxia-telangiectasia (11 male, mean age 13.1±4.9 years) and 17 with Common variable immunodeficiency (8 males, mean age 28.5±11.3 years). Classification of nutritional status and percentage of fat mass were evaluated. 25-hydroxyvitamin D was analyzed by high performance liquid chromatography and deficiency was considered when 25-hydroxyvitamin D< 20 ng/mL. Malnutrition was the most common nutritional disorder: 7/14 (50%) and 4/17 (23.5%) in Ataxia-telangiectasia and Common variable immunodeficiency groups, respectively. We found a high percentage of 25-hydroxyvitamin D deficiency in the Ataxia-telangiectasia group 6/14 (42.8%) and Common variable immunodeficiency group 3/17 (17.6%). There was no association between vitamin D deficiency and high-sensitivity C-reactive protein, lymphocyte count (CD3, CD4 and CD8) and body fat percentage. Considering the frequency of autoimmune diseases and infections in patients with primary immunodeficiencies, strict monitoring of the vitamin levels are recommended with the aim to reduce morbidity.