Nutrigenomics of Vitamin D

Abstract

Nutrigenomics studies how environmental factors, such as food intake and lifestyle, influence the expression of the genome. Vitamin D3 represents a master example of nutrigenomics, since via its metabolite 1α,25-dihydroxyvitamin D3, which binds with high-affinity to the vitamin D receptor, the secosteroid directly affects the epigenome and transcriptome at thousands of loci within the human genome. Vitamin D is important for both cellular metabolism and immunity, as it controls calcium homeostasis and modulates the response of the innate and adaptive immune system. At sufficient UV-B exposure, humans can synthesize vitamin D3 endogenously in their skin, but today’s lifestyle often makes the molecule a true vitamin and micronutrient that needs to be taken up by diet or supplementation with pills. The individual’s molecular response to vitamin D requires personalized supplementation with vitamin D3, in order to obtain optimized clinical benefits in the prevention of osteoporosis, sarcopenia, autoimmune diseases, and possibly different types of cancer. The importance of endogenous synthesis of vitamin D3 created an evolutionary pressure for reduced skin pigmentation, when, during the past 50,000 years, modern humans migrated from Africa towards Asia and Europe. This review will discuss different aspects of how vitamin D interacts with the human genome, focusing on nutritional epigenomics in context of immune responses. This should lead to a better understanding of the clinical benefits of vitamin D.

Efficacy of Vitamin D3 Buccal Spray Supplementation Compared to Other Delivery Methods: A Systematic Review of Superiority Randomized Controlled Trials

“…An additional limitation of the included RCTs is the lack of vitamin D genetic variants assay. As with most procedures in the human body, vitamin D absorption and utilization are also epiphenomena related to hereditary susceptibility, which suggests a personalized response [10,70]. Hence, genetic variations in 25-hydroxylase and vitamin D-binding protein have been shown to alter supplementation response [71,72], although the produced effect appears small compared to that of lifestyle components [69].…”

“…independently extracted characteristics of the retrieved RCTs and outcomes of interest from full-text articles. Extracted data involved (1) the number of participants at each stage, (2) participant characteristics, (3) study characteristics (registry, design, ethical approval, country, funding), (4) administered dose of vitamin D3 and methods of delivery, (5) intervention duration, (6) washout period (whenever applicable), (7) participant recruitment sites, (8) assays and kits for determining 25(OH)D levels, (9) baseline and post-intervention results (including 25(OH)D, Ca, and parathyroid hormone (PTH) concentrations), (10) recorded adverse events, (11) drop-outs, and (12) analysis performed (intention-to-treat or per protocol).…”

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

“…In detail, UVB radiation (wavelength in the 290–315 nm range) penetrates uncovered skin providing energy for two subsequent non-enzymatically reactions, which occur in the plasma membranes of keratinocytes and fibroblasts [ 7 , 8 , 9 , 10 , 11 , 12 ]. Through the opening of its B ring, 7-DHC is first photo-converted in pre-vitamin D 3 , a thermodynamically unstable molecule, which is further thermo-isomerised to vitamin D 3 via a slow temperature-dependent reaction ( Figure 2 ) [ 9 , 10 , 12 , 13 , 14 ].…”

“…Modern lifestyle—including indoor living with insufficient sun exposure or the use of sunscreen [ 74 , 75 ] to prevent skin burns and cancer [ 76 ]—can significantly reduce endogenous vitamin D production [ 4 , 12 ]. For this reason, an adequate vitamin D intake through food or supplements became crucial [ 23 , 77 , 78 , 79 ].…”

“…Foods containing adequate levels of this micronutrient include cod liver oil and fatty fishes, such as swordfish, sardines, mackerel, salmon and tuna. Beef liver, egg yolks, yogurt and cheese represent additional natural sources of vitamin D, although contain it only in modest amounts [ 12 , 14 , 18 ]. Vitamin D in these foods is mainly present as D 3 form [ 83 ], while some mushrooms provide the D 2 form in variable amounts, the content of which is boosted by UV exposure [ 6 ].…”