Hypovitaminosis D: a new risk marker for cardiovascular disease.

Abstract

1. Joseph P. McConnell, PhD[⇑][1] 1. is director, Cardiovascular Laboratory Medicine, The Mayo Clinic and Foundation, Rochester, MN 2. Kevin F. Foley, PhD, MT 1. is a clinical chemist, Kaiser Permanente NW Laboratories, Portland, OR 3. Gina M. Vargas, PhD 1. is director, Importadora y Laboratorio Clinico ATM SRL: Cochabamba, Bolivia 1. Address for Correspondence: Joseph P. McConnell PhD, Mayo Clinic; Cardiovascular Laboratory Medicine, Rochester, Minnesota, (507) 284-0524, Fax: (507) 266-2888, Email: mcconnell.joseph{at}mayo.edu 1. Differentiate and define the various forms of vitamin-D, including Vitamin D2, D3 25(OH)D and 1,25(OH2)D. 2. Describe current opinion concerning vitamin-D dosing recommendations as well as issues around establishing a normal reference range. 3. Identify several diseases and pathologies for which hypovitaminosis D has been implicated. 4. Explain the correlations between serum 25(OH)D levels and the cardiovascular risk factors of hypertension and metabolic syndrome. 5. Describe the overall relationship between hypovitaminosis D and cardiovascular disease and the need for future studies to demonstrate causality. INTRODUCTION Vitamin D has a well-established role in calcium and phosphorus metabolism and bone mineralization. Vitamin D deficiency causes rickets in children, and in adults can lead to osteomalacia, resulting in muscle and bone weakness. Data are emerging that link hypovitaminosis D, as assessed by measurement of 25-hydroxyvitamin D [25(OH)D], with cardiovascular pathology. Vitamin D deficiency has been associated with hypertension, some inflammatory markers, and metabolic syndrome. More recently, low serum 25(OH)D has been associated with increased incidence of cardiovascular events and all-cause mortality. In this review, we discuss the role of vitamin D in health, and describe recent evidence linking hypovitaminosis D to cardiovascular disease. We describe controversies surrounding recommended daily intake and optimal serum levels, as well as discuss the need for further research relating vitamin D deficiency with cardiovascular disease. Vitamin D deficiency Vitamin D, which has also been referred to as the “sunshine vitamin” is a lipid-soluble vitamin obtained from both exogenous and endogenous sources. Some foods, such as eggs, fatty fish, and liver naturally contain vitamin D, but other dietary sources of vitamin D are from fortified foods, like milk and cereals, or from nutritional supplements1. Most of the body's vitamin D is produced endogenously following exposure of skin to sunlight, thus geography, season, skin tone, and sun exposure are primary predictors of vitamin D nutritional status2. Vitamin D obtained from sun is in the form of vitamin D3 (cholecalciferol), while vitamin D2 (ergocalciferol) or D3 may be obtained from dietary sources. Vitamin D2 differs… 1. Differentiate and define the various forms of vitamin-D, including Vitamin D2, D3 25(OH)D and 1,25(OH2)D. 2. Describe current opinion concerning vitamin-D dosing recommendations as well as issues around establishing a normal reference range. 3. Identify several diseases and pathologies for which hypovitaminosis D has been implicated. 4. Explain the correlations between serum 25(OH)D levels and the cardiovascular risk factors of hypertension and metabolic syndrome. 5. Describe the overall relationship between hypovitaminosis D and cardiovascular disease and the need for future studies to demonstrate causality. [1]: #corresp-1