Peer-reviewed research concerning vitamin d, summarized and appraised in plain language with every source cited.
This systematic review and meta-analysis set out to see whether vitamin D supplements raise testosterone or related markers in men. It pooled randomized trials measuring total testosterone, SHBG (sex hormone-binding…
This study looked at how high-intensity exercise and vitamin D3 supplements affect vitamin D levels differently in trained athletes versus untrained men. It compared 22 mixed martial arts athletes and…
This study looked at whether vitamin D levels are linked to metabolic health, measured by the TyG index (a score from fasting blood sugar and triglycerides that flags insulin resistance,…
This study looked at whether vitamin D changes how well metformin (a common diabetes drug that lowers blood sugar) can bring down prolactin (a pituitary hormone that suppresses testosterone when…
This study looked at whether vitamin D3 supplementation improves hormone levels and semen quality in infertile men. It pooled data from six randomized controlled trials involving 945 men, measuring changes…
This study looked at whether vitamin D levels in the blood are linked to developing sarcopenia (age-related muscle loss) in older adults. It followed 1,292 Korean adults aged 70-84 without…