Skip to main content

Advertisement

Table 1 Studies investigating the relationship between vitamin D status and semen parameters in healthy and infertile men

From: Vitamin D and assisted reproduction technologies: current concepts

Author, year, [reference #] Country Study design Cases included Sample size Groups of patients identified by serum 25(OH)D levels Statistical analysis used Main finding(s) Main confounding factors considered
Ramlau-Hansen et al., 2011 [29] USA Cross-sectional Healthy men aged 18-21 307 3-24 ng/ml: low (33.5%) 25–37 ng/ml: medium (33.5%) 38–91: high (33%) Spearman’s rank correlation test; Multivariable linear regression No significant association between 25(OH)D levels and sperm parameters Season
BMI
History of diseases
Duration of abstinence
Time from ejaculation to analysis
Blomberg Jensen et al., 2011 [27] USA Cross-sectional Healthy men aged 18-21 300 <10 ng/ml: deficient (12%) 10-20 ng/ml: insufficient (32.7%) 21-30 ng/ml : sufficient (41.7%) >30 ng/ml: high (13.7%) Kruskal Wallis test; Multivariable linear regression Positive association between 25(OH)D levels and sperm progressive motility and morphology FSH
Duration of abstinence
Time from ejaculation to analysis
Serum calcium levels
Season
Hammoud et al., 2012 [30] USA Cross-sectional Healthy men aged 18-67 147 <20 ng/ml: deficient (12.4%) 20-49 ng/ml: intermediate (75.2%) ≥50 ng/ml: high (12.4%) Multivariable linear regression Negative association of both deficient and high 25(OH)D levels with sperm parameters Season
Age
BMI
Alcohol intake
Smoking
Yang et al., 2012 [31] China Cross-sectional Healthy and infertile men aged 20-40 195 (healthy group); 364 (infertile group) <10 ng/ml: severely deficient 10-20 ng/ml: deficient 21-30 ng/ml: insufficient >30 ng/ml : sufficient Spearman’s rank correlation test; Multivariable linear regression Positive association between 25(OH)D levels, sperm motility and morphology also in the infertile group Testosterone
Season
Duration of abstinence
Time from ejaculation to analysis