ArticleAndrology2026
Vitamin D levels and biomarkers of male fecundity: A study from the Danish National Birth Cohort.
Article in Andrology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
Abstract
backgroundVitamin D is metabolised throughout the male reproductive system, suggesting a direct regulatory role of vitamin D in male reproduction.
objectivesTo investigate the association between plasma vitamin D levels at sperm ejaculation and during spermatogenesis and biomarkers of male fecundity in young men. MATERIALS AND
methodsFrom the Fetal Programming of Semen Quality cohort, Denmark, 2017-2019, 1047 young men provided a semen and a blood sample, and self-measured their testes volume at a clinical visit. Plasma levels of vitamin D (25(OH)D
resultsCompared to measured vitamin D levels >75 nmol/L, levels <25 nmol/L at sperm ejaculation were associated with lower total sperm count (‒15% [95% confidence interval: ‒33%; 8%]), and a higher proportion of non-progressive and immotile spermatozoa (11% [95% confidence interval: 0%; 24%]). Lower measured vitamin D levels were also associated with higher oestradiol, lower sex hormone-binding globulin and lower follicle-stimulating hormone, in dose-dependent manners. Vitamin D levels estimated before and during spermatogenesis yielded similar associations as vitamin D levels measured at sperm ejaculation. DISCUSSION: By using the seasonal variation in endogen vitamin D synthesis, we were able to estimate individual vitamin D levels during spermatogenesis.
conclusionLower vitamin D levels before and during spermatogenesis and at sperm ejaculation were associated with lower total sperm count and sperm motility and an altered reproductive hormone profile.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.