Peer-reviewed research concerning vitamin d, summarized and appraised in plain language with every source cited.
This study looked at whether time spent outdoors is linked to testosterone in men. It analyzed 2,205 men in the US National Health and Nutrition Examination Survey, tracking daily outdoor…
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 set out to see whether exposure to bright light is linked to testosterone in men, an area far less studied than diet and exercise. It analyzed data from…
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 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 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 set out to identify which factors might influence pregnancy success in couples undergoing assisted reproductive technology (ART, fertility treatments that handle eggs and sperm outside the body). It…
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…
This study set out to test whether vitamin D supplements raise testosterone in healthy men. It randomly assigned 98 men with normal testosterone but low vitamin D to a high…
This study looked at whether vitamin D levels track with testosterone, and with hypogonadism (when the testicles do not make enough testosterone, which shows up as low drive, fatigue and…