Calcium & Testosterone
You’ve heard as calcium being beneficial for bone health, but there’s actually a human study that observed its interaction with testosterone:
30 healthy male athletes were randomly split into 3 groups:
1) No exercise and 35 mg calcium/kg of bodyweight,
2) Exercise at 90-min/day, 5 days a week and 35 mg calcium/kg of bodyweight,
3) Exercise at 90-min/day, 5 days a week with no calcium supplementation.
Testosterone levels were determined at 3 time intervals:
- before supplementation,
- 4 weeks after supplementation,
- at rest,
- and following a training session.
Researchers concluded that training increases testosterone levels, and that this increase is greater if accompanied by calcium supplementation (1).
So yes, calcium supplementation is associated with higher testosterone levels.
(source)