Table 2 Clinical and non-clinical effect of Vitamin D on various target organs

Inhibits in vitro HCV replication in a dose-dependent manner

Liver

[55]

Vitamin D supplementation may improve SVR rate in HCV among various genotypes

Liver

[128]

Low vitamin D level leads to non-responsiveness to interferon based treatment

Liver

[164,165,166]

Vitamin D deficiency causes downregulation of 25-hydroxylase CYP27A1 in, liver resulting in increased fibrosis and low SVR

Liver

[164, 167]

Deficiency causes increase in fibrosis and inflammation in liver

Liver

[164,165,166, 168, 169]

Supplementation/phototherapy improves liver histology in preclinical studies of NAFLD

Liver[NAFLD]

[170, 171]

Supplementation prevents liver fibrosis in preclinical studies

Liver[NAFLD]

[171, 172]

Low vitamin D level causes severe steatosis, inflammation and fibrosis

Liver[NAFLD]

[167, 169, 173, 174]

Vitamin D deficiency causes increased hepatic expression of TLR2, TLR4 and TLR9, which are implicated in NAFLD pathogenesis

Liver[NAFLD]

[174]

Vitamin D increases Ca and PO₄ absorption from small intestine

Calcium and Bone

[175]

It Suppresses PTH secretion and Induces osteoclast maturation

Calcium and Bone

[175, 176]

Normal vitamin D level lowers prevalence of metabolic syndrome by 67%

Pancreatic functions

[177]

Supplementation improves insulin sensitivity and lowers risk of developing type 2 diabetes

Pancreatic functions

[178]

Vitamin D deficiency increases chances of insulin resistance

Pancreatic functions

[179]

Impaired pancreatic β-cell function in cases of low vitamin D level

Pancreatic functions

[180, 181]

Low level of vitamin D decreases macrophage TLR response and increase chances of TB infection

Innate Immunity

[182]

Vitamin D is essential for NK cell development and function

Innate Immunity

[183]

Vitamin D Inhibits proliferation of Th1 lymphocytes

Adaptive Immune System

[184]

Supplementation decreases risk of developing MS in women and type 1 diabetes in children

Adaptive Immune System

[177, 185]

Low vitamin D level increases risk of M. tuberculosis infection

Immunity

[186,187,188,189]

Normal Vitamin D level decreased population incidence of autoimmune diseases such as MS

Immunity

[190]

Higher 25(OH)D levels associated with lower incidence of colorectal adenoma

Carcinogenesis

[191]

Sunlight exposure associated with reduced risk of NHL

Carcinogenesis

[192]

Vitamin D decreased risk of colon, breast and prostate cancer

Carcinogenesis

[193,194,195,196,197,198]

Vitamin D deficiency is associated with bone weakness and painful crises

SCD

[199, 200]

vitamin D deficiency and its potential association with acute pain in SCD

SCD

[38]