Effect of serum 25-hydroxyvitamin D levels on sperm quality and assisted reproductive technology outcomes for men of infertile Chinese couples

Joint and individual associations between multiple vitamins and sperm quality in adult men

Background

Several studies have suggested that a healthy diet is associated with improved male fertility outcomes. However, the joint and individual associations between the status of multiple vitamins and sperm quality remain unclear.

Objectives

This study aimed to investigate the associations between serum vitamin levels and sperm quality parameters in adult men.

Methods

A cross-sectional study was conducted among 156 adult men seeking fertility care at a reproductive center from December 2023 to June 2024. Blood and semen were collected on the same day to determine the concentrations of nine kinds of vitamins (B1, B2, B6, B9, B12, C, A, D, E) and five parameters of sperm quality [total sperm number, sperm concentration, progressive motile sperm, morphologically normal rate, and DNA fragment index (DFI)]. The joint and individual associations between vitamin levels and sperm quality were analyzed using multiple linear regression and Bayesian kernel machine regression (BKMR) models.

Results

Increased tertiles of vitamin B1 and 1,25-dihydroxyvitamin D3 [1,25-(OH)2-D3] in serum were associated with higher sperm quality (all P for trends < 0.10). Compared with the lowest tertiles, the highest tertiles of vitamin B12 had β: 3.0 (95% CI: 0.8, 5.2) increasing in DFI, and vitamin A was negatively associated with progressive sperm motility (P for trends = 0.05). We generally found null results between multiple vitamin levels and the parameters of sperm quality in the BKMR models.

Discussion

These research findings imply that vitamins could have a dose-dependent dual effect on sperm quality. More specifically, the impact of vitamins varies according to their dosage levels and types. Personalized vitamin supplementation may be more effective than taking multivitamins in improving sperm quality.

Correlation between serum vitamin B12, vitamin D, and suboptimal semen parameters in male infertility: A hospital-based cross-sectional study

Background

Micronutrients such as vitamin B12 and D have recently gained attention for their potential roles in male reproductive health. Despite their significance, there's a critical gap in understanding their association with male infertility, particularly concerning suboptimal semen parameters. This study aimed to address this knowledge gap by examining serum vitamin B12 and D levels in infertile males, providing insights that could inform targeted interventions for couples facing male infertility challenges.

Methods

This cross-sectional study, conducted at Tertiary Health care centre in north India for 2 years, enrolled 73 infertile males aged 20-40 years from the fertility clinic (participants exhibited suboptimal semen parameters). Clinical and demographic data were collected through interviews and record reviews, while semen samples underwent meticulous processing for the analysis of various parameters. Blood samples were collected after overnight fasting for serum vitamin B12 (ELISA) and vitamin D (CLIA) assessment. Statistical analyses, performed using SPSS, included t-tests, Chi-square tests, and Pearson's correlation analyses to explore associations between serum vitamin levels and semen parameters, with a significance level set at P < 0.05.

Results

The study comprised 73 infertile males with suboptimal semen parameters. Serum vitamin B12 levels (mean ± SD: 243.4 ± 69.3 pg/mL) and vitamin D levels (22.5 ± 13.2 ng/mL) were measured. Low vitamin B12 (<200 pg/mL) was observed in 29 participants (39.7%), while low vitamin D (<20 ng/mL) was noted in 51 participants (69.9%). Semen parameters revealed significant differences in sperm count, motility, and morphology between low and normal vitamin B12 groups. Similar patterns were observed with vitamin D levels, emphasizing potential associations between vitamin status and semen quality.

Conclusion

Our findings suggest a potential link between low serum vitamin B12 and D levels and suboptimal semen parameters in infertile males. Addressing these nutritional deficiencies may hold promise for improving male fertility outcomes. Further research is warranted to elucidate the mechanisms involved and explore targeted interventions.

Socioeconomic status and vitamin D deficiency among women of childbearing age: a population-based, case-control study in rural northern China

OBJECTIVE

To explore the association between socioeconomic status (SES) and vitamin D deficiency/insufficiency of women of childbearing age in rural northern China.

DESIGN

A population-based, case-control study was conducted.

SETTING

Four counties of Henan Province, China from 2009 to 2010.

PARTICIPANTS

1151 non-pregnant healthy women between 18 and 40 years old.

PRIMARY AND SECONDARY OUTCOME MEASURES

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using high-performance liquid chromatography-tandem mass spectrometry. Vitamin D insufficiency was defined as serum 25(OH)D ≥20 ng/mL and <30 ng/mL, deficiency as ≥10 ng/mL and <20 ng/mL, and severe deficiency as <10 ng/mL. SES was measured separately by women's and their husbands' education level and occupation, household income and expenditure, as well as aggregately by SES index constructed with principal component analysis.

RESULTS

The median serum 25(OH)D level was 20.90 (13.60-34.60) ng/mL, and the prevalence of vitamin D insufficiency, deficiency and severe deficiency was 20.16%, 31.80% and 15.99%, respectively. After adjustment, household annual income <¥10 000 was associated with increased risk of vitamin D insufficiency (adjusted OR (aOR): 2.10, 95% CI 1.41 to 3.14), deficiency (aOR: 1.58, 95% CI 1.09 to 2.29) and severe deficiency (aOR: 2.79, 95% CI 1.78 to 4.38); inadequate household income for expenditure was associated with elevated risk of vitamin D insufficiency (aOR: 1.66, 95% CI 1.08 to 2.54) and deficiency (aOR: 1.81, 95% CI 1.26 to 2.62); low SES index was associated with elevated risk of vitamin D insufficiency (aOR: 2.40, 95% CI 1.52 to 3.80) and deficiency (aOR: 1.64, 95% CI 1.08 to 2.50); and both middle and low SES index were associated with increased risk of vitamin D severe deficiency (aOR: 1.70, 95% CI 1.02 to 2.84; aOR: 2.45, 95% CI 1.45 to 4.14).

CONCLUSIONS

Lower SES was associated with higher risk of vitamin D deficiency/insufficiency in women of childbearing age in rural northern China. More should be done to explore potential mechanisms and to narrow down SES inequalities in vitamin D status.