Is there a role for vitamin D in human reproduction?

Abstract

Vitamin D is a steroid hormone with canonical roles in calcium metabolism and bone modeling. However, in recent years there has been a growing body of literature presenting associations between vitamin D levels and a variety of disease processes, including metabolic disorders such as diabetes and prediabetes and autoimmune conditions such as thyroid disease. This review focuses on the potential role of vitamin D in both male and female reproductive function. The vitamin D receptor (VDR) is expressed throughout central and peripheral organs of reproduction. VDR is often co-localized with its metabolizing enzymes, suggesting the importance of tissue specific modulation of active vitamin D levels. Both animal and human studies in males links vitamin D deficiency with hypogonadism and decreased fertility. In females, there is evidence for its role in polycystic ovary syndrome (PCOS), endometriosis, leiomyomas, in-vitro fertilization, and pregnancy outcomes. Studies evaluating the effects of replacing vitamin D have shown variable results. There remains some concern that the effects of vitamin D on reproduction are not direct, but rather secondary to the accompanying hypocalcemia or estrogen dysregulation.

Correlation of Vitamin D3 (Calcitriol) Serum Concentrations with Vitamin B12 and Folic Acid in Women Undergoing in vitro Fertilisation/Intracytoplasmatic Sperm Injection

“…In addition, a vitamin D receptor response element (VDRE) in the PCFT promoter region -1,694/+1,680 was suggested and a transcriptional response to D3 in that region was confirmed [2]. In conclusion, and in line with our results, D3 and VDR seem to be necessary for the cellular folic acid uptake [2,29] (Fig. 3).…”

“…Vitamin B12-IF complexes are resistant with respect to the decomposition of gastric acid. Notably, an uptake of B12-IF complexes is calcium-dependent [2,16]. A vitamin B12 deficiency thus leads to an indirect folic acid deficiency even if adequate folic acid exists [16].…”

Connection between Endometriosis and Vitamin D – True or False?

“…Despite the "vitamin" name, its source is not completely dietary and over 85% is generated in the skin following exposure to ultraviolet light. For detailed description of chemistry and biological effects of vitamin D, see an excellent review by Nandi et al (2016). Besides the principal role in bone homeostasis, vitamin D is involved in additional biological processes such as modulation of cell growth, immune functions and reduction of inflammation.…”

Vitamin D deficiency among selected group of Sudanese housewives

“…These are 25-hydroxylation and 1-a-hydroxylation. 1 As the initial reaction takes place principally in the liver with 25-hydroxylase, the second one occurs mainly in the kidneys with 1-a-hydroxylase (1, 25-dihydroxyvitamin D [1,25(OH)2D3]). 2 This structure of vitamin D has a high affinity for binding to vitamin D receptors (VDRs) in target tissue (2).…”