It is well know that testosterone is the hormone that supports muscle growth. The levels vary from person to person, but maintaining testosterone levels naturally is one of the best ways to gain muscle mass. Actually, testosterone can also:
* Increase bone mineral density
* Thicken body hair and skin
* Improve sexual desire
* Boost energy
* Decrease irritability and depression
* Improve cognitive function
That being said, Vitamin A is essential in producing testosterone and for proper use of protein by our bodies. What many people may not know though, is that Vitamin A is not only depleted by a high intake of protein, but it is also necessary for the synthesis of new protein, which is the goal of someone who is trying to gain muscle mass. Therefore friends, if you are like me and want to efficiently gain and maintain muscle mass make sure to incorporate foods high in Vitamin A into your diet. Liver, egg yolks, butter from grass fed cows and cod liver oil are excellent sources!