Effects of vitamin D on sex steroids, luteinizing hormone, and testosterone to luteinizing hormone ratio in 307 infertile men

Influence of cholecalciferol supplementation on changes in total 25OHD, free 25OHD, and free 25OHD % in relation to calcium, bone, and glucose homeostasis in young, infertile men

BACKGROUND AND OBJECTIVE

While all types of vitamin D metabolites are bound to vitamin D binding protein and albumin leaving only a small fraction in its free active form, only serum concentrations of total 25-hydroxy vitamin D (25OHD) are used to determine vitamin D status in clinical practice. This study aimed to describe the association of total 25-hydroxy vitamin D (25OHD), calculated free 25OHD, and free 25OHD% (free 25OHD × 100 %/total 25OHD) with mineral, bone, and metabolic variables and assess the impact of cholecalciferol supplementation.

RESEARCH DESIGN AND METHODS

Secondary data from a single-center, double-blinded, randomized, placebo-controlled clinical trial (NCT01304927) in 307 infertile men. The treatment group (n = 151) initially received 300,000 IU cholecalciferol as a bolus followed by 1400 IU daily for 150 days and was compared to a placebo group (n = 156).

RESULTS

At baseline men with free 25OHD% > 0.03 % had lower serum triglycerides (mmol/L) (0.8 vs. 1.0; p = 0.002), lower LDL (mmol/L) (2.7 vs. 3.1; p = 0.003), lower fasting blood glucose (mmol/L) (4.9 vs. 5.2; p = 0.012), and lower PTH (pmol/L) (3.8 vs. 4.6; p = 0.015) compared to men with free 25OHD% < 0.02 %. When the study population was stratified according to total 25OHD or free 25OHD, the metabolic markers and bone variables did not show any differences. Cholecalciferol supplementation increased total 25OHD after 150 days compared to placebo and the difference was highest in men with lowest vitamin D status. Cholecalciferol supplementation did not change free 25OHD%.

CONCLUSION

The free 25OHD% is better associated with metabolic health markers such as serum triglycerides, LDL, and fasting blood glucose, but not bone or calciotrophic markers except parathyroid hormone. The free 25OHD% is not affected by cholecalciferol supplementation.

The Impact of Vitamin D on Androgens and Anabolic Steroids among Adult Males: A Meta-Analytic Review

BACKGROUND

Recent studies indicate that vitamin D impacts male reproductive function, with deficiency linked to infertility. This review evaluates the effect of vitamin D supplementation on male fertility, focusing on total testosterone, free testosterone, the free androgen index (FAI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex-hormone-binding globulin (SHBG), and estradiol.

METHODS

We systematically searched Medline, Web of Science, Cochrane Library, and Scopus from their inception until July 2024 for randomized controlled trials (RCTs) involving adult males. The primary focus of these studies was on reproductive hormone parameters, analyzed using a random-effects meta-analysis and weighted mean difference (WMD). Evidence quality was assessed using ROB2 and GRADE. Meta-regression and dose-response analyses were performed.

RESULTS

Seventeen studies met the criteria for quantitative analysis. Vitamin D supplementation significantly increased total testosterone levels (WMD 0.38, 95% CI 0.06-0.70, n = 15, I2 = 67.03). However, it had no significant effect on other hormone parameters: free testosterone (WMD 0.00, 95% CI -0.02-0.03, n = 9, I2 = 48.12), FSH (WMD -0.02, 95% CI -0.57-0.53, n = 7, I2 = 48.72), LH (WMD -0.09, 95% CI -0.30-0.12, n = 8, I2 = 0.00), SHBG (WMD 0.73, 95% CI -1.14-2.61, n = 10, I2 = 69.05), FAI (WMD -0.92, 95% CI -2.12-0.27, n = 6, I2 = 0.00), and estradiol (WMD -0.02, 95% CI -2.95-2.92, n = 5, I2 = 20.63).

CONCLUSION

This meta-analysis shows that vitamin D supplementation may increase total testosterone levels in men. However, further well-designed RCTs are needed to determine vitamin D's effects on other reproductive hormone parameters.

High-dose cholecalciferol supplementation to obese infertile men is sufficient to reach adequate vitamin D status

Obesity is associated with low vitamin D status, and the optimal supplement and dosage of cholecalciferol (vitamin D3) or calcidiol (25OHD) for individuals with obesity have been debated. We aimed to determine the effect of high-dose vitamin D3 supplementation on achieving adequate vitamin D levels among infertile men with normal weight v. obesity. Here, we present secondary end points from a single-centre, double-blinded, randomised clinical trial, comprising 307 infertile men randomised to active or placebo treatment for 150 days. Men in the active group initially received an oral bolus of 300 000 mg of vitamin D3, followed by daily supplementation with 1400 mg of vitamin D3 and 500 mg of calcium. Baseline BMI was listed as a predefined subgroup. At baseline, serum 25OHD was significantly higher in men with normal weight (BMI < 25 kg/m2) compared with men with overweight (BMI 25-30 kg/m2) and obesity (BMI > 30 kg/m2) (48 nmol/l v. 45 nmol/l and 39 nmol/l, respectively; P = 0·024). After the intervention, men with normal weight, overweight and obesity treated with vitamin D3 had a significantly higher serum 25OHD compared with corresponding placebo-treated men (BMI < 25 kg/m2: 92 nmol/l v. 53 nmol/l, BMI = 25-30 kg/m2: 87 nmol/l v. 49 nmol/l and BMI > 30 kg/m2: 85 nmol/l v. 48 nmol/l; P < 0·001 for all, respectively). In conclusion, we show that high-dose vitamin D3 supplementation to infertile men with obesity and low vitamin D status is sufficient to achieve adequate serum 25OHD levels.

High-dose vitamin D3 supplementation shows no beneficial effects on white blood cell counts, acute phase reactants, or frequency of respiratory infections

BACKGROUND

Vitamin D has been suggested to influence the immune system, and vitamin D metabolites and the vitamin D receptor (VDR) are generated and expressed in white blood cells (WBC). Moreover, vitamin D status has been associated with incidence and prognosis of some respiratory tract infections (RTI). Therefore, we investigated the effect of vitamin D3 supplementation on WBC, acute phase reactants (APR), and the risk of developing RTIs.

METHODS

A double-blinded, randomized, placebo-controlled clinical trial of 307 infertile men with multiple secondary immunological endpoints. The vitamin D3 group (n = 151) initially received 300,000 IU (7,500 µg) cholecalciferol once - followed by 1,400 IU (35 µg) daily for 150 days. The placebo group (n = 156) did not receive active ingredients.

RESULTS

At baseline, stratification into clinically relevant groups of vitamin D status (< 25; 25-50; 50-75; >75 nmol/L), showed an inverse association with total leucocyte concentrations (7.0 vs. 6.0 vs. 6.0 vs. 5.5 (109/L); p = 0.007), lymphocytes (2.4 vs. 2.1 vs. 2.0 vs. 2.0 (109/L); p = 0.048), CRP (2.0 vs. 1.7 vs. 1.2 vs. 1.2 (mg/L); p = 0.037), and orosomucoid (0.82 vs. 0.77 vs. 0.76 vs. 0.70 (g/L); p = 0.015). After 150 days, no differences were detected in WBC counts or APRs between the vitamin D3 and the placebo group. However, vitamin D3 treated men had a higher prevalence of self-reported RTIs compared with the placebo group (55% vs. 39%; p = 0.005).

CONCLUSIONS

High-dose vitamin D3 supplementation did not alter WBCs or APRs, but a higher prevalence of respiratory infections was observed in the vitamin D3 group. Serum 25(OH)D3 was negatively correlated with most WBCs, indicating that vitamin D status may be linked with inflammation and WBC turnover, but not an important determinant of developing RTIs.

TRIAL REGISTRATION

NCT01304927 (ClinicalTrials.gov). Registered February 20, 2011.

Sarcopenia and Diabetes: A Detrimental Liaison of Advancing Age

Sarcopenia is an age-related clinical complaint characterized by the progressive deterioration of skeletal muscle mass and strength over time. Type 2 diabetes (T2D) is associated with faster and more relevant skeletal muscle impairment. Both conditions influence each other, leading to negative consequences on glycemic control, cardiovascular risk, general health status, risk of falls, frailty, overall quality of life, and mortality. PubMed/Medline, Scopus, Web of Science, and Google Scholar were searched for research articles, scientific reports, observational studies, clinical trials, narrative and systematic reviews, and meta-analyses to review the evidence on the pathophysiology of di-abetes-induced sarcopenia, its relevance in terms of glucose control and diabetes-related outcomes, and diagnostic and therapeutic challenges. The review comprehensively addresses key elements for the clinical definition and diagnostic criteria of sarcopenia, the pathophysiological correlation be-tween T2D, sarcopenia, and related outcomes, a critical review of the role of antihyperglycemic treatment on skeletal muscle health, and perspectives on the role of specific treatment targeting myokine signaling pathways involved in glucose control and the regulation of skeletal muscle metabolism and trophism. Prompt diagnosis and adequate management, including lifestyle inter-vention, health diet programs, micronutrient supplementation, physical exercise, and pharmaco-logical treatment, are needed to prevent or delay skeletal muscle deterioration in T2D.