Testosterone and its effects on the body are much studied, and that research continues. But some things about this naturally occurring hormone are clear. Testosterone appears to be part of a man’s regulatory systems for bone mass, muscle mass and sex drive. And it’s also clear that as men age, their production of testosterone begins to decrease.

Testosterone supplements can be prescribed, but there’s also a dietary element to the production of the hormone. To make testosterone, men need to take in the building blocks of testosterone in the forms of vitamins A, C and D and essential trace elements such as zinc.

Here are several foods that can provide the nutrients necessary for testosterone production:

+ Eggs – The protein, cholesterol and omega-3 fatty acids present in eggs are used in testosterone production.

+ Oysters – Zinc is critical for the testosterone-making process, and one of the best ways to get zinc is via oysters. A single serving of oysters provides the full recommended daily allowance of zinc. While eating oysters raw is a popular method, the FDA says oysters should be cooked before eating to avoid the potentially life-threatening bacteria known as vibrio vulnificus.

+ Spinach – This leafy green provides a shot of magnesium, which has been shown in studies to promote higher testosterone levels.

+ Garlic – Fresh garlic is thought to release a hormone that triggers testosterone building in the body.

+ Salmon – Not only does salmon contain the building block omega-3, it also contains a healthy dose of magnesium.

+ Tuna – Speaking of fish, tuna contains an ample amount of vitamin D, and it packs a lot of healthy protein, too.

Doctors also recommend losing weight, which has a positive effect on testosterone production, and participating in muscle-forming workouts, which is known to provide at least a temporary boost in testosterone levels.