The role of vitamin D in hepatic metastases from colorectal cancer

Can vitamin D be an adjuvant therapy for juvenile rheumatic diseases?

Vitamin D, known for its essential role in calcium and bone homeostasis, has multiple effects beyond the skeleton, including regulation of immunity and modulation of autoimmune processes. Several reports have shown suboptimal serum 25 hydroxyvitamin D [25(OH)D] levels in people with different inflammatory and autoimmune rheumatic conditions, and an association between 25(OH)D levels, disease activity and outcomes. Although most available data pertain to adults, insights often are extended to children. Juvenile rheumatic diseases (JRDs) are a significant health problem during growth because of their complex pathogenesis, chronic nature, multisystemic involvement, and long-term consequences. So far, there is no definitive or clear evidence to confirm the preventive or therapeutic effect of vitamin D supplementation in JRDs, because results from randomized controlled trials (RCTs) have produced inconsistent outcomes. This review aims to explore and discuss the potential role of vitamin D in treating selected JRDs. Medline/PubMed, EMBASE, and Scopus were comprehensively searched in June 2023 for any study on vitamin D supplementary role in treating the most common JRDs. We used the following keywords: "vitamin D" combined with the terms "juvenile idiopathic arthritis", "juvenile systemic scleroderma", "juvenile systemic lupus erythematosus", "juvenile inflammatory myopathies", "Behcet disease", "periodic fever syndromes" and "juvenile rheumatic diseases". Observational studies have found that serum 25(OH)D concentrations are lower in juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, juvenile systemic scleroderma, Behcet disease and proinflammatory cytokine concentrations are higher. This suggests that vitamin D supplementation might be beneficial, however, current data are insufficient to confirm definitively the complementary role of vitamin D in the treatment of JRDs. Considering the high prevalence of vitamin D deficiency worldwide, children and adolescents should be encouraged to supplement vitamin D according to current recommendations. More interventional studies, especially well-designed RCTs, assessing the dose-response effect and adjuvant effect in specific diseases, are needed to determine the potential significance of vitamin D in JRDs treatment.

Newly-identified Pathways Relating Vitamin D to Carcinogenesis: A Review

BACKGROUND

The epidemiological relationship between vitamin D levels and cancer has been thoroughly investigated. Published data from large studies appear to corroborate a significant relationship between higher serum vitamin D concentrations and improved survival. Mechanistic reviews on commonly-studied cancers - including breast cancer, colon cancer and melanoma - focus predominantly on data from older studies. In outlining avenues for future research, we believe there is utility in summarizing novel findings introduced to the literature.

MATERIALS AND METHODS

In this narrative review, we used MEDLINE, PUBMED and Cochrane databases to identify mechanistic studies published from January 1, 2015 onwards exploring this topic.

RESULTS

Twenty-five mechanistic studies were included in this review. It was found that vitamin D plays a critical role in both direct (i.e. tumor gene expression, proliferation, invasiveness, sensitivity to chemotherapy etc.) and indirect (i.e. effects on the tumor microenvironment and immunomodulation) tumor suppression mechanisms.

CONCLUSION

These newly-identified pathways warrant further research, with the hopes that we may understand how and when vitamin D supplementation can be integrated into precision medicine therapeutics for cancers of the breast, colon and skin. Cancer care providers should consider recommendations to screen for vitamin D deficiency in this population.