Vitamin D up date 2015: from bone to general preventive healthcare

Vitamin D deficiency: Recent findings in the region

Mario Flores

Instituto Nacional de Salud Pública, Cuernaaca, México

Introduction / Objectives: Vitamin D (VD) is essential for bone health and calcium metabolism. However, recent studies have suggested other non-calcemic functions of VD, including: cell proliferation and differentiation, regulation of the immune system, insulin secretion, among others. These novel functions of VD had motivated an increasing interest in the vitamin recently. Studies worldwide have shown an inadequate VD status for populations of both developed and developing countries. The situation in Latin America has been described in a recent work by Brito, et al (1). This presentation is based mostly in the aforementioned study (1) and updated with other informartion. The objective of this presentation is to give an update on the vitamin D status among LA countries. Development:Vitamin D status in the region, by population group: Children In a nationally representative sample of 6,827 Mexican children 1-11 y from the 2012 Mexican National Health and Nutrition Survey (ENSANUT), mean serum 25-OH-D concentration was 57.3±16 nmol/L. Overall, vitamin D insufficiency (25-OH-D < 50 nmol/L) was observed in 33% of children. Thirty percent of preschool children (1-5y) had vitamin D insufficiency, compared to 36% school-aged children (6-11y) (p<0.001). Vitamin D insufficiency was observed in 37% of girls, compared to 29% of boys (p<0.001). Thirty-six percent of children living in urban areas had vitamin D insufficiency, compared to 26% of children in rural areas (p<0.001) (2). Another study in school-age children in northern Mexico showed 27% of obese children with VD insufficiency (25-OH-D <50 nmol/L); the corresponding figure for non-obese children was 13% (1). In Brazil, a study in 84 children 2-7 y beneficiaries of a milk-fortification program, mean 25-OH-D level was 49.7+30 nmol/L. Prevalence of VD insufficiency was 58% (3). The Argentinean National Health Survey found only 3% of children 6-23 mo with VD deficiency (serum 25-OH-D < 25 nmol/L) in the Patagonian region (1). In Colombia, according to two studies in school children, the prevalence of VD insufficiency (25- OH-D < 50 nmol/L was between 10-12 % (1) Adolescents A study in 136 Brazilian adolescents (16-20 y) in Sao Paulo reported mean 25-OH-D levels of 73+22 nmol/L, and a 60% prevalence of values between 25<75 nmol/L (4). In 2006, a nationally representative sample of 503 Mexican adolescents found 8% with VD insufficiency (25-OH-D < 50 nmol/L) and 23 % with suboptimal VD levels (25-OH-D < 75 nmol/L) (5). Adults In a national sample of 964 Mexican adults, the prevalence of VD insufficiency was 9.8%, whereas 20% had suboptimal VD concentrations (5). In postmenopausal Brazilian women, a prevalence of 7% VD deficiency (25-OH-D < 25 nmol/L) was found (1). Elderly A study in 108 healthy older Mayans in Guatemala reported mean serum 25-=H-D values of 53.3+15 nmol/L, and a prevalence of 46% below 50 nmol/L (1) In Ecuador, a study reported 19% of elderly men with VD insufficiency (25-OH-D < 40 nmol/L), whereas in elderly women the prevalence was 9% (1). In a random sample of 150 elderly Mexican adults (>60y) from a national survey (ENSANUT 2006) the prevalence of VD insufficiency (25-OH-D < 50 nmol/L) was 12%, and 33% were below 75 nmol/L (5). A study in elderly Argentinean subjects showed a prevalence of VD deficiency (25-OH-D <25 nmol/L) between 2-16% in different regions; however no deficiency was found in the summer (1). In Brazil, a study in elederly adults foun 82 to 94% < 70 nmol/L, and 16% < 25 nmol/L (1). Conclusions: There is evidence of risk of vitamin D deficiency (serum 25- OH-D 25<50 nmol/L) in different age and population groups in Latin America. However, nationally representative studies are uncommon and more data are needed to assess the magnitude of this public health proble. Key words: vitamin D, nutritional deficiencies, bone health. Acknowledgement. The author would like to thank Instituto Danone de Mexico for supporting funds for VD determinations in ENSANUT 2012. References. 1. Brito A, Cori H, Olivares M, Mujica MF, Cediel G, Romaña DL. Less than adequate vitamin D status and intake in Latin America and the Caribbean: a problem of unknown magnitude. Food Nutr Bull 2013;34(1):59-64. 2. Flores M, Villalpando S, Macias N, Contreras A, Robledo R. (personal communication). 3. Yukari A, Augusto RA, Martins F, Araujo L. Vitamin A and D status among child participants in a food supplementation program. Cad Saude Pública 2015;31(3):531-542. 4.Emo-Peters BS, dos Santos LC, Fisberg M, Wood RJ, Araujo L. Prevalence of vitamin D insufficiency in Brazilian adolescents. Ann Nutr Metab 2009;54:15-21. 5. Flores M, Barquera S, Sanchez L, Lozada A, Macias N, Díaz E. Concentraciones séricas de vitamina D en ninos, adolescentes y adultos mexicanos Resultados de la ENSANUT 2006. Available at: http://www.insp.mx/images/stories/Centros/cinys/Docs/111202_ReporteVitaminaD.pdf Accesed: June 4th, 2015.