Vitamin D₃ in cancer prevention and therapy: the nutritional issue

Abstract

The action of vitamin D3, in its biological form 1α,25(OH)2vitD3 or calcitriol, may be summarized as a steroid-like hormone able to modulate basic functions of cell encompassing energy balance, stress response, mitochondria biogenesis, intracellular calcium oscillations, and replication/apoptosis mechanisms leading to cell survival. Moreover, calcitriol exerts a potent role as an innate and adaptive immune cytokine as immunity is closely related to self-maintenance through its energetic/metabolic balance and homeostasis of cell turnover. Therefore, vitamin D might be the ancestral form of survival hormones developed with calcified vertebrate bearing skeleton in order to survive far from water. This characteristic may suggest that the role of dietary vitamin D in preventing cancer is simply ancillary to the many factors playing a major role in contrasting impairment in energy balance and cell survival. Most probably, the immune role of calcitriol might be included in the maintenance, mostly by adipose tissue, of an anti-inflammatory, tolerant immune status, depending on the immune tolerance and modulation from the gut. A balance closely modulated by the leptin axis, which when impairments in metabolism occur, such as in insulin resistance or obesity, calcitriol is unable to face at this imbalance, while leptin plays a major role and cancer progression may be promoted. Furthermore, this mechanism promotes epithelial/mesenchymal transition-mediated fibrosis, leading to cancer resistance to immune control and drug action. Interestingly, this pathologic picture is triggered by deficiency in vitamin D from the diet. Therefore, a dietary habit including vitamin D sources, besides flavonoids, may ameliorate lifestyle and health span in most individuals, depending on their genetic background.

Lower Serum Vitamin D Level Was Associated with Risk of Dry Eye Syndrome

“…Vitamin D has demonstrated anti-inflammatory effects in different pathological processes [ 24 ]. For instance, vitamin D could decrease the inflammatory response of cancer and inhibited the proliferation of cancer cells in-vitro [ 25 ]. Considering that inflammation was one of the key pathogenesis and phenotype of DES, higher level vitamin D would decreased the inflammatory response in the ocular surface and then improve the severity of DES.…”

Knowledge and Perceptions of Vitamin D Deficiency Among the United Arab Emirates Population

“…An adequate Vitamin D serum level has also been reported to enhance the immune system, prevent cancer, and limit its progression. In addition, Vitamin D plays a role in the prevention and control of diabetes [10][11][12][13][14][15][16].…”

Vitamin D Deficiency and Its Determinants in Adults: A Sample from Community-Based Settings in the United Arab Emirates

“…Studies suggest that sufficient serum vitamin D of more than 30 nmol/L is implicated in preventing cardiovascular disease [6]. An adequate vitamin D serum level has also been reported to enhance the immune system, prevent cancer, and limit its progression [7]. In addition, vitamin D plays a role in the prevention and control of diabetes through improving glycemic index [8], enhancing beta cell function, increasing insulin secretion, and decreasing insulin resistance [9–12].…”