VITAMIN D IN HEALTH AND DISEASE: Vitamin D for Health and in Chronic Kidney Disease

Abstract

Vitamin D is taken for granted and is not appreciated for its importance in overall health and well-being. Vitamin D, known as the sunshine vitamin, is appreciated as being important for the prevention of rickets in children. It is now recognized that vitamin D is important for not only the growing skeleton, but for the maintenance of a healthy musculoskeletal system throughout life. Vitamin D deficiency in adults precipitates and exacerbates osteoporosis and causes the painful bone disease osteomalacia. The revelation that vitamin D is biologically inactive and requires sequential hydroxylations in the liver and kidney to form 1,25-dihydroxyvitamin D helps explain why patients with renal failure are often resistant to vitamin D and suffer from secondary hyperparathyroidism and renal osteodystrophy. In addition to its role in maintaining calcium and phosphorus homeostasis, vitamin D is now being recognized as important for maintaining maximum muscle strength and for the prevention of many chronic diseases, including type I diabetes, multiple sclerosis, rheumatoid arthritis, hypertension, cardiovascular heart disease, and many common cancers. Vitamin D status is best determined by the measurement of circulating levels of 25-hydroxyvitamin D. Vigilance for maintaining a 25-hydroxyvitamin D level of at least 20 ng/ml and preferably 30-50 ng/ml has important benefits for both healthy children and adults, as well as children and adults suffering from chronic kidney disease.

Etiological Role of Ferritin and Vitamin D in Patients with Telogen Effluvium

“…This deficiency was more common in veiled Kuwaiti women compared with non-veiled women. Vitamin D plays an important role in the absorption of calcium, another mineral that is essential for hair health and Omega 3 fatty acids contained in vitamin D help to protect the scalp from bacteria and other microorganisms and promote blood circulation in the scalp [10].…”

“…Absorption of calcium that is essential for hair health needs presence of vitamin D. Omega 3 fatty acids contained in vitamin D help to protect against mico-organisms and promotion of scalp circulation [10].…”

Recovery of Hyperphosphatoninism and Renal Phosphorus Wasting One Year after Successful Renal Transplantation

“…This figure was slightly higher than what was observed in the CKD counterparts. Given this high prevalence of vitamin D insufficiency, the many pleiotropic effects of native vitamin D (33), and the association of vitamin D deficiency with incident cardiovascular disease (34), a more liberal vitamin D supplementation policy should be considered in CKD patients as well as in RTR. Meanwhile, additional prospective and interventional studies should be initiated to definitely proof the benefits of this policy.…”

Paricalcitol Attenuates Renal Interstitial Fibrosis in Obstructive Nephropathy

“…Therefore, dysfunction of tubular epithelial cells and/or loss of renal parenchyma as seen in diseased kidney consequently would cause a deficit in the production and supply of active vitamin D. The possibility also exists that vitamin D may be required for maintaining the structural and functional integrity of normal tubular epithelium. Along this line, deficiency of active vitamin D could be a causative factor that contributes to the progressive loss of renal function (6,9). In this context, supplementation of active vitamin D might be a rational strategy to break up the vicious cycle between vitamin D deficiency and CKD progression, thereby leading to a mitigation of renal pathologic lesions and dysfunction (10).…”

“…Most, if not all, pleiotropic actions of vitamin D and its analogues are mediated by the specific vitamin D receptor (VDR), a ligand-dependent transcription factor that belongs to the steroid nuclear receptor gene family (3,4). Clinical studies demonstrate that deficiency of active vitamin D is a common feature in patients with chronic kidney disease (CKD) (5)(6)(7)(8). This observation comes as little surprise, because renal proximal tubular epithelial cells, after all, are the major sites of calcitriol synthesis and uptake of its precursor in vivo.…”