The Role of Vitamin D in Male Fertility - A Focus on the Testis
Written by Ben Bunting: BA(Hons), PGCert.
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In this article, we focus on the role of vitamin D in male fertility. We learn about the role of vitamin D in male reproduction, including its effects on the testis, where it is expressed in high concentrations. We also learn about how vitamin D affects male sperm morphology and motility.
TT levels were significantly lower in patients with serum vitamin D levels 12 ng/mL
One study examined the associations between serum vitamin D levels and prostate cancer. In patients with a history of prostate cancer, serum vitamin D levels were significantly lower than those of controls. The effects of dietary vitamin D and calcium supplementation were not statistically significant. Patients with serum vitamin D levels greater than or equal to 400 IU/day had fewer cases of breast cancer. However, more research is needed to confirm these findings.
Patients with serum vitamin D levels greater than or equal to 12 ng/mL were less likely to develop delirium. However, the researchers note that these results are based on a single episode. Further studies should examine if the association persists or if it is recurrent.
Low levels of serum vitamin D may reduce the ability to detect the protective effect of the vitamin. While this study did not examine the protective effect of vitamin D on a wider range of health outcomes, the findings suggest that low vitamin D levels may hinder the ability of the vitamin to detect the protective effect of vitamin D on a population.
Serum vitamin D levels are an important indicator for improving the health of the bones. Low levels of vitamin D may contribute to a higher risk of bone pain, poor immune function, and cardiovascular disease. Vitamin D may also decrease the risk of falling.
Sperm motility was lower
The benefits of dietary supplements are well-documented in the field of male infertility. Studies have suggested that supplemental calcium, vitamin D, and vitamin E may improve sperm motility and increase sperm count. Moreover, these vitamins are essential for reproductive health and have antioxidant properties. In addition to increasing sperm motility, they also boost sperm morphology. In one study, men who consumed a vitamin D-C-based supplement for three months had an increased rate of pregnancy.
One study in Denmark found that men with low vitamin D levels were at greater risk of sperm motility. Interestingly, those with high vitamin D levels had higher sperm motility, while those with low levels showed reduced motility. The findings were based on a cross-section of young men.
Another important factor that affects sperm motility is a lack of iron. Iron helps regulate pH and fluidity, which are vital for sperm. Ferritin is found in testicular tissue called the sertoli. Iron is also needed for mitochondrial redox reactions to take place, which require oxygen. When there is insufficient iron in the body, the transport of oxygen to the testes is affected, causing a hypoxic environment. If the semen is not able to reach the mitochondria, the sperm will not be able to complete their mission.
The researchers compared semen and hormonal parameters in men with genetic variations of CHDH. They found that men with CHDH gene variation had decreased sperm motility. Further, SNPs in genes that metabolize choline and folate increased the need for dietary choline. Ultimately, these genetic changes affect the homeostasis of endogenous phosphatidylcholine.
Sperm morphology was less normal in men with low serum vitamin D levels
A recent study examined if serum vitamin D levels affected sperm morphology. In men with low levels of vitamin D, sperm morphology was less normal. However, men with normal vitamin D levels had normal sperm morphology.
Researchers suggested that vitamin D may play an important role in male reproductive function, semen quality, and androgen status. Semen samples from infertile men with low levels of vitamin D showed decreased motility and concentration of sperm. In this study, men were assigned to one of two groups: those receiving vitamin D3 or placebo treatment. The vitamin D group received 4000 IU of vitamin D daily for three months, while the control group received a placebo.
Serum vitamin D levels also affected sperm morphology. Men with low levels of vitamin D had lower total and linear progressive motility and morphology. In this study, serum vitamin D levels were significantly associated with sperm motility. The authors concluded that the effects of vitamin D on sperm motility may influence a man's infertility.
Serum vitamin D levels correlated with all sperm parameters, but not with oxidative stress markers. This suggests that the positive effect of vitamin D on male fertility is mediated by an alternate pathway. Vitamin D increases the production of 4-HNE, a molecule that is produced when the tyrosine nitration process occurs. This compound damages sperm protein structure and function, resulting in decreased morphology.
Vitamin D receptors are expressed in the human male reproductive tract
Vitamin D receptors are found in various organs of the human male reproductive tract, including the testis. They are thought to be involved in regulating spermatogenesis. The function of the receptor depends on the presence and activity of metabolizing enzymes and circulating VD levels. However, the role of the receptor in the male reproductive tract remains unclear.
A study published in the American Journal of Human Genetology has identified five different tissues where vitamin D receptors are expressed. These tissues include the human genital tract, skin, kidney, testis, and uterus. The authors concluded that vitamin D is involved in the regulation of sperm motility and in the development of the male reproductive tract.
The physiology of vitamin D is complex, with unique activities and actions in particular cell types and tissues. For example, vitamin D deficiency in the elderly is associated with muscle weakness. However, whether this effect is directly related to vitamin D deficiency remains unclear. Moreover, recent studies have indicated that VDR is expressed in the liver but is not immunologically detectable.
The VDR has several functional roles, including regulation of bone metabolism and the absorption of calcium. Because it is a major mediator of vitamin D hormone activities, it may also represent a therapeutic target. In addition, early studies indicated that certain forms of rickets may be caused by inherited defects in the VDR. These defects result in altered gene expression and decreased ability to regulate transcription. Consequently, the affected tissues fail to maintain mineral homeostasis and skeletal and hard-tissue deformities.
Genetic variations influence nutrient metabolism
Genetic variations influence the response of the human body to various nutrients and bioactives. These variations may affect the risk of male infertility. Hence, the analysis of nutrigenomic data is important to understand how these variations can influence male fertility. The following sections describe some of the pathways influenced by genetic variation and their contribution to male infertility.
Dietary fats affect several metabolic processes. Some of these nutrients act as cofactors for enzymes and as a component of proteins. They are needed for DNA synthesis, repair, and methylation. Genetic variants that impact these factors may negatively affect male fertility and fetal growth and birth outcomes. This is why it is important to consider the overall health of an individual, including dietary factors, to preserve fertility.
Male fertility depends on normal spermatogenesis. This process is complex and involves one-carbon metabolism. The nutrient folate is important for nucleotide synthesis, methylation, and DNA protection. Hence, adequate intake of folate can benefit male fertility.
Genetic variations influence nutrient metabolism in male reproduction by regulating choline dehydrogenase and CHDH. The latter affects the endogenous phosphatidylcholine homeostasis and increases the need for dietary choline.
Conclusion
There is a growing body of evidence pointing to the important role of vitamin D in male fertility. This essential vitamin influences several aspects of male fertility, including spermatogenesis and hormone production. Testicular hormones, such as testosterone, are necessary for proper spermatogenesis and the maturation and differentiation of spermatids.
A study found that low serum vitamin D concentrations were associated with altered semen parameters. Despite the potential link between low vitamin D and male infertility, further comprehensive studies are needed to confirm and validate this association. Supplementation of vitamin D is one way to increase serum levels and testis function.
Interestingly, some studies have found that vitamin D supplements improve sperm progression and quality. In one study, vitamin D supplementation increased spontaneous conceptions and live birth rates in men with oligoasthenozoospermia. In another study, vitamin D supplementation increased sperm motility, but did not affect semen parameters. The differences between the two studies may be due to differences in the study design and different cut-off values.
The sample size was small, and it is unclear whether the study's results were affected by other factors. However, the researchers did note that the results of this study were significantly related to testosterone, free testosterone, and estradiol levels. Further, VitD levels significantly correlated with sperm vitality, progressive sperm motility, and sex hormone-binding globulin levels.
