Genetic polymorphisms of vitamin D metabolism genes and serum level of vitamin D in colorectal cancer

The Global Prevalence of Vitamin D Deficiency in the Elderly: A Meta-analysis

Background

Vitamin D deficiency is widely prevalent among the elderly, posing significant health risks. This study aims to determine the global prevalence of vitamin D deficiency in the elderly.

Methods

A systematic review and meta-analysis was conducted, examining databases including Scientific Information Database (SID), Medline (PubMed), ScienceDirect, Scopus, Embase, and Google Scholar until January 2023. The publication bias of the studies was assessed using the I2 test of heterogeneity and the Egger test.

Results

The prevalence of vitamin D deficiency, defined as levels below 20 ng or 50 nmol was found to be 59.7% (95% CI 45.9-72.1). Furthermore, a review of six studies involving 6748 elderly individuals showed a prevalence of 27.5% (95% CI 21.8-34.1) for deficiency defined between 20 and 30 ng or 50-75 nmol. Additionally, a meta-analysis of seven studies with a sample size of 6918 elderly individuals reported a prevalence of 16% (95% CI 10.2-24.1) for deficiency defined above 30 nmol or 75 nmol.

Conclusion

The results of the present study reveal that the prevalence of vitamin D deficiency among the elderly is high and requires the attention of health policymakers at the World Health Organization to prioritize extensive information dissemination and screening to mitigate the adverse effects on their quality of life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-023-01089-w.

Genetic variants in the vitamin D pathway and their association with vitamin D metabolite levels: Detailed studies of an inner-city pediatric population suggest a modest but significant effect in early childhood

OBJECTIVES

In a large cohort of healthy infants and toddlers 6-36 months of age (n = 776), we have been exploring the potential role of genetic variation in predisposition to vitamin D insufficiency. The genes encoding the key cytochrome P450 hydroxylases (CYP2R1, CYP24A1, and CYP27B1) harbour recurrent mutations of uncertain effect. This study was undertaken to look for biochemically relevant associations of these variants with inter-individual differences in vitamin D metabolism in an at-risk pediatric population.

METHODS

Genotyping for CYP2R1-CT (c.-1127 C>T, rs10741657), CYP24A1-AG (c.-686A>G, rs111622401), and CYP27B1-CA (c.-1261 C>A, rs10877012) mutations were performed using SNaPshot assay, followed by Sanger sequencing confirmation. Vitamin D metabolites and vitamin D binding protein (DBP) were measured by established methods.

RESULTS

In a multivariate regression model, with corrections for co-variates, subjects with the homozygous CYP2R1-TT variant had significantly higher concentrations of 25(OH)D, free 25(OH)D, and 24,25(OH)2D levels. In subjects with the CYP24A1-AG mutation, concentrations of 25(OH)D were significantly higher.

CONCLUSIONS

The CYP2R1-TT and CYP24A1-AG variants have measurable effects on the vitamin D pathway. It seems unlikely that they will be clinically relevant in isolation, but they may be members of the large pool of infrequent mutations contributing to different risks for the vitamin D deficiency phenotype.

Vitamin D deficiency in elderly: Risk factors and drugs impact on vitamin D status

Introduction:

Vitamin D (VD) deficiency is a major public health problem worldwide. In spite of its high prevalence, particularly among elderly people, VD deficiency is still underestimated by many physicians. Increasingly, VD deficiency is associated with several known geriatric syndromes.

Methods:

The study sample consisted of 125 patients, aged 75 years and older, admitted to the acute geriatric unit. The plausible association between the serum 25-hydroxyvitamin D [25(OH)D] level and patient age, sex, body mass index, renal function, cholecystectomy history, and the prescribed drugs had been investigated. The Fisher's exact test was used to conduct the statistical analysis of data.

Results:

Surprisingly, furosemide treatment was correlated with normal 25(OH)D levels and an increased incidence of secondary hyperparathyroidism. Unlike the other four parameters mentioned above, our data showed that only the patient sex exhibited a significant association with 25(OH)D level as elderly males suffered from a serious VD deficiency as compared to elderly females.

Conclusion:

Old age is an independent risk factor for VD deficiency. The supplementary dose of VD should be precisely defined to achieve the optimal serum 25(OH)D level in elderly people. The definition of the normal serum 25(OH)D threshold in elderly furosemide-treated patients is worth of further studies.

CYP27B1 Gene Polymorphism rs10877012 in Patients Diagnosed with Colorectal Cancer

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide. Intestinal cells are CYP27B1 gene expression sites and, as a consequence, they are capable of converting pro-vitamin D into the active paracrine and autocrine forms. It was demonstrated that rs10877012 polymorphism in the CYP27B1 gene influenced the circulating vitamin D level. This provided a rationale for determining the role that this polymorphism plays in the risk of developing colon cancer. In this study, we investigated the association of rs10877012 (T/G) polymorphism in the CYP27B1 gene with CRC susceptibility. The study population (n = 325) included CRC patients (n = 106) and healthy controls (n = 219). DNA was extracted from peripheral leukocytes and analyzed for the CYP27B1 polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We found an association between the presence of the T allele at the polymorphic site (odds ratio (OR) = 2.94; 95% CI 1.77–4.86; p < 0.0001) and a decreased CRC incidence.

The association of serum vitamin D-binding protein and 25-hydroxyvitamin D in pre-operative and post-operative colorectal cancer

Background

The association between vitamin D–binding protein (VDBP) and 25‐hydroxyvitamin D (25 (OH)D) with colorectal cancer (CRC) is still ambiguous. This study was to further investigate the relationship between serum VDBP, 25 (OH)D levels and the clinical and pathological features of patients with CRC.

Methods

Enzyme‐linked immunosorbent assay (ELISA) and chemiluminescence immunoassay were used to analyze the VDBP and 25(OH)D concentrations in serum. Pearson's correlation analysis was applied to evaluate the association between serum VDBP and 25(OH)D levels in CRC. Conditional logistic regression was performed to analyze the prediction value of serum VDBP or 25(OH)D as a risk factor for CRC.

Results

The serological levels of 25(OH)D in patients were significantly lower than in healthy individuals, while VDBP levels were significantly higher than in healthy controls. The serum VDBP in pre‐operative was significantly lower than in post‐operative samples, while the serum 25(OH)D from pre‐operative patients was significantly higher than post‐operative patients. Patients with tumors with higher stage and increased lymph node involvement had lower serum post‐operative VDBP levels. In addition, our results showed that the pre‐operative VDBP level is a risk factor of CRC.

Conclusions

The levels of serum 25(OH)D and VDBP were both associated with CRC. Thus, serum 25(OH)D and VDBP levels might be of value in evaluating the pathogenesis and risk of CRC in the future. Moreover, serum VDBP or 25(OH)D levels were associated with patient's clinical and pathological features providing data for risk and prognostic prediction.

Vitamin D and the skin: what should a dermatologist know?

Although first discovered in 1931, vitamin D has seen an increased interest in the scientific community over the past decades, including the dermatology field. Vitamin D promotes calcium and phosphorus absorption; however, the actions of vitamin D are not confined to bone. Indeed, there is now overwhelming and compelling scientific data that vitamin D plays a crucial role in a plethora of cellular function and in extra-skeletal health. Except for fatty fish livers, very few foods naturally contain vitamin D; and the major source of vitamin D comes from skin exposure to sunlight via ultraviolet B. Keratinocytes are unique in the body as not only do they provide the primary source of vitamin D for the body, but they also possess both the enzymatic machinery to metabolize the vitamin D produced to active metabolites. This has been referred to as the photoendocrine vitamin D system. Vitamin D regulates keratinocytes proliferation and differentiation; and plays a role in the defense against opportunistic infections. Multiple factors are linked to vitamin D status; and a growing number of dermatologic diseases has been linked to vitamin D status such as atopic dermatitis, psoriasis, vitiligo, and cutaneous cancers. In this article, we reviewed the potential determinants of vitamin D status, as its implications in dermatologic diseases.

The burgeoning role of cytochrome P450-mediated vitamin D metabolites against colorectal cancer

The metabolites of vitamin D₃ (VD3) mediated by different cytochrome P450 (CYP) enzymes, play fundamental roles in many physiological processes in relation to human health. These metabolites regulate a variety of cellular signal pathways through the direct binding of activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Thus, the polymorphisms of VDR and VD3 metabolizing enzymes lead to differentiated efficiency of VD3 and further affect serum VD3 levels. Moreover, VDR activation is demonstrated to inhibit the growth of various cancers, including colorectal cancer. However, excessive intake of vitamin D may lead to hypercalcemia, which limits the application of vitamin D tremendously. In this review, we have summarized the advances in VD3 research, especially the metabolism map of VD3 and the molecular mechanisms of inhibiting growth and inducing differentiation in colorectal cancer mediated by VDR-associated cellular signal pathways. The relationship between VDR polymorphism and the risk of colorectal cancer is also illustrated. In particular, novel pathways of the activation of VD3 started by CYP11A1 and CYP3A4 are highlighted, which produce several noncalcemic and antiproliferative metabolites. At last, the hypothesis is put forward that further research of CYP-mediated VD3 metabolites may develop therapeutic agents for colorectal cancer without resulting in hypercalcemia.

High Levels of Circulating Type II Collagen Degradation Marker (CTx-II) Are Associated with Specific VDR Polymorphisms in Patients with Adult Vertebral Osteochondrosis

Both vitamin D and collagen have roles in osteocartilaginous homeostasis. We evaluated the association between the circulating 25-hydroxyvitamin D (25(OH)D) type I and II collagen degradation products (CTx-I, and CTx-II), and four vitamin D receptor gene (VDR) polymorphisms, in Italian males affected by low back pain (LBP) due to herniation/discopathy and/or vertebral osteochondrosis. FokI, BsmI, ApaI, and TaqI VDR-polymorphisms were detected through PCR-restriction fragment length polymorphism (RFLP), and circulating 25(OH)D, CTx-I and CTx-II were measured by immunoassays in 79 patients (of which 26 had osteochondrosis) and 79 age-, sex- and body mass index (BMI)-matched healthy controls. Among all 158 subjects, carriers of FF and Ff genotypes showed lower 25(OH)D than ff, which suggested a higher depletion of vitamin D in F allele carriers. Higher CTx-I concentrations were observed in TT versus Tt among controls, and Tt versus tt among LBP cases, which suggested a higher bone-cartilaginous catabolism in subjects bearing the T allele. Higher CTx-II concentrations were observed in patients with osteochondrosis bearing FF, bb, TT, or Aa genotypes in comparison with hernia/discopathy patients and healthy controls. Vertebral osteochondrosis shows peculiar genotypic and biochemical features related to vitamin D and the osteocartilaginous metabolism. Vitamin D has roles in the pathophysiology of osteochondrosis.