In this regard, vitamin D deficiency has been linked with several diseases such as autoimmune disorders, osteoarthritis, and cancer, in which chronic inflammation might be a causative factor. Furthermore, there is a decline in the level of androgens and estrogens, which have been linked with suppression of IL-6, a proinflammatory cytokine. These shifts in the T cell population change the cytokine expression profile. Aging is associated with changes in the immune system, with a decline in the number of naïve T cells in favor of an increase in memory T cells, and with a relative increase of Th2 cell versus Th1 cells. It has also been observed that sufficient 25(OH)D levels are related to increasing concentrations of IL-4 and IL-10 and to low levels of proinflammatory cytokines such as IL-1, IL-6, IL-12, IL-17, IL-23, and IFN- γ. Thus, vitamin D deficiency might result in the impaired function of immune cells and cytokine imbalance. Activated VDR binds response elements on DNA that are associated with antimicrobial and immune regulatory functions. While the CYP27B1 in the kidneys is regulated by parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), and 1,25(OH)2D3, its production in the immune system cells is driven by inflammatory conditions, either directly by the presence of cytokines or in response to activation through the vitamin D receptor (VDR). In addition to the kidneys, many other tissues and cells throughout the body, including immune cells, express CYP27B1 and are therefore capable of regulating their own 1,25(OH)2D3 local concentration. It requires further metabolism by the 1-alpha hydroxylase (CYP27B1) in the kidneys to produce the biologically active form 1,25-dihydroxyvitamin D (1,25(OH)2D3). The main source of Vitamin D comes from sun exposure of the skin, from 7-dehidrocholesterol in response to ultraviolet B radiation (UVB), to further be metabolized in the liver to 25-hydroxyvitamin D 25(OH)D which is the metabolite used to assess vitamin D status. Vitamin D deficiency was correlated with TNF- α serum levels, possibly increasing the susceptibility of older adults to a proinflammatory state and its related diseases. A cutoff point of 74 years of age determined probability of vitamin D hipovitaminosis. Remarkably, an increase in one centimeter in WC decreased 25(OH)D by 0.176 ng/mL, while an increase in one point BMI decreased 25(OH)D by 0.534 ng/mL. 25(OH)D levels remained below 74 years) combined with WC (>88 cm) and BMI (>32.7) showed a high probability (90%) of vitamin D deficiency. Vitamin D deficiency/insufficiency was found in 91.3% of the subjects despite living in appropriate latitude (25☄0′0″N). The same cohort was followed during 12 months. We performed a multivariate analysis considering lifestyle factors, anthropometric, and inflammatory markers according to seasonal variation in Mexican healthy older adults.
Stats modeling the world vitamin d deficiency australia skin#
Ageing decreases pre-vitamin D production in the skin and is associated with altered cytokine profile. Vitamin D deficiency is present even in sunny regions.