Vitamin D

Abstract

Interest in vitamin D and the VDR gene is increasing as putative roles in human health and evolutionary processes are explored. This review looks beyond the classic biochemistry that links vitamin D to calcium homeostasis; it explores how vitamin D interacts with light in a broader perspective than simple skin photosynthesis. It examines how the vitamin influences circadian rhythm, and how it may have helped drive the evolution of skin pigmentation. To this end, the nutrient-nutrient relationship with folate is also explored. The VDR gene is additionally examined as a factor in the evolutionary selection of skin depigmentation at higher latitudes to allow vitamin D synthesis. Evidence is given to show that VDR polymorphisms exhibit a latitudinal gradient in allele prevalence consistent with such a paradigm. Overall, the review examines new evo-devo ideas that link light-sensitive vitamins to human health/phenotype, both within and across the lifecycle.

The Vitamin D–Folate Hypothesis as an Evolutionary Model for Skin Pigmentation: An Update and Integration of Current Ideas

“…These ethnic differences in the allele frequency likely reflect an adaption to different UVR regimes. This is supported by a recent study reporting multiple loci involving the VDR gene that display strong latitudinal clines [ 73 ] and previous work of the present authors in showing positive associations between the carriage of several VDR variant alleles ( Fok1 , Bsm1 , Apa1 , and Taq1 ) and latitude (as a surrogate measure of UVR exposure) [ 74 ]. Ancestral alleles for Bsm1 , Fok1, and Taq1 variants are associated to increases in cytokine production [ 75 ], immune cell response [ 76 ], and VDR expression [ 77 ], respectively.…”

Plasma Vitamin D Deficiency Is Associated With Poor Sleep Quality and Night-Time Eating at Mid-Pregnancy in Singapore

“…Alternatively, 1,25OHD may also directly interact with circadian clock genes to control their gene expression [5]. Given that sunlight drives both vitamin D synthesis [7] and circadian rhythms [2], it is possible that vitamin D transduces light signals to regulate circadian rhythms [49]. Another explanation for the present findings may be that plasma 25OHD concentrations may be a surrogate measure of retinal sunlight exposure [50] which entrains the human circadian clock [39].…”

A Brief Introduction to the Exposome and Human Health

“…Both short-term human adaptation (epigenetic change) and long-term evolutionary change can occur due to variations in exposure to key vitamins. 22,23 The food exposome represents the totality of dietary exposures, 24 and is a substantial challenge to examine due to the wide range of foods consumed and the variability in the amount and frequency of intake, which are modulated by food preference, season, and other factors. 24 Fortunately, two vitamins have such profound biological effects that their dietary abundance, and physicochemical loss (folate) or biosynthesis (vitamin D) through secondary environmental exposure (UV exposome) have shaped the human phenome from both evolutionary and health perspectives.…”

“…37,38 Ultimately, the UV exposome-folatevitamin D multiplex interacts with a cassette of polymorphic genes that are known to be altered in the longer term to adapt the human skin phenome to the prevailing UV exposome. 22,23,26…”