Studies about vitamin D and testosterone:
Vitamin D Treatment Improves Levels of Sexual Hormones, Metabolic Parameters and Erectile Function in Middle-Aged Vitamin D Deficient Men (2017)
Conclusion: In a 12-month study of 102 vitamin D-deficient middle-aged men, monthly high-dose vitamin D therapy raised their testosterone levels, improved erectile function, and reduced body fat.
Vitamin D Deficiency and Low Ionized Calcium Are Linked with Semen Quality and Sex Steroid Levels in Infertile Men (2016)
Conclusion: In a prospective study of 1248 Danish men, those with adequate vitamin D levels had slightly higher testosterone levels and much higher sperm counts compared to those with deficient vitamin D levels.
Conclusion: 12 months of vitamin D therapy revealed to be effective for improving testosterone production in rats and for reversing testicular damage from hyperglycemia-induced inflammation.
Association Between Serum 25-Hydroxyvitamin D and Serum Sex Steroid Hormones Among Men in NHANES (2016)
Conclusion: This study found a positive correlation between vitamin D levels and testosterone levels in men. More vitamin D = more testosterone.
Association Between 25(OH)-Vitamin D and Testosterone Levels: Evidence from Men with Chronic Spinal Cord Injury (2016)
Conclusion: In a study of male spinal cord injury patients, those with lower vitamin D levels also had lower testosterone levels.
Vitamin D is Associated with Testosterone and Hypogonadism in Chinese Men: Results from a Cross-Sectional SPECT-China Study (2015)
Conclusion: In a study of 2,854 Chinese men, those with hypogonadism had “significantly lower” vitamin D levels.
Vitamin D is Significantly Associated with Total Testosterone and Sex Hormone-Binding Globulin in Malaysian Men (2015)
Conclusion: A study of Malaysian men found that those with lower vitamin D levels also had lower testosterone levels.
Serum 25-Hydroxyvitamin D Levels and Testosterone Deficiency in Middle-Aged Korean Men: A Cross-Sectional Study (2015)
Conclusion: A study of 652 Korean men over the age of 40 found that those with higher vitamin D levels also had higher testosterone levels.
Conclusion: A study of 3,051 European men over the age of 40 from eight different locations found that testosterone levels were lower among the vitamin D-deficient men.
Conclusion: In this study of 1,362 men, those with higher vitamin D levels also had higher testosterone levels.
Conclusion: A year-long randomized control trial involving 162 men found that those who supplemented with 3,000 IU of vitamin D daily experienced significant testosterone increases compared to the placebo group.
Conclusion: In a study of 2,299 men, those with higher vitamin D levels also had higher testosterone levels compared to men with lower vitamin D levels.
Also see studies on vitamin D and
Athlete’s Edge: Faster, Quicker, Stronger with Vitamin D by Dr. John Cannell (Amazon link)