Optimal Vitamin D levels in Children with Chronic Kidney Disease

The vitamin D is an essential factor for skeletal development, and its deficiency can cause growth retardation and skeletal deformities such as rickets [1,2]. Vitamin D3 (cholecalciferol) sourced from diet and ultraviolet B sunlight is metabolized to 25(OH) vitamin D (25(OH)D, calcidiol) in the liver, and then in the kidney to 1,25(OH)2 vitamin D (1,25(OH)2D, calcitriol) which is the biologically active form [1,2]. Additionally, non-renal production of 1,25(OH)2D in skin, colon, prostate, macrophage, and parathyroid has been reported [2]. Calcitriol binds to vitamin D receptor (VDR) within the cells, and acts in intestine, bone, immune cells, and tumor microenvironment [2-4]. The VDR has been reported to be found in endocrine glands, cardiovascular tissues, and hematopoietic cells, and vitamin D has been supposed to be involved to both skeletal disease and nonskeletal diseases including metabolic syndrome, insulin resistance, obesity, cardiovascular diseases, infection, allergy, and cancer [2-5].