One tablespoon of semen has approximately 20 calories. Semen also contains zinc and calcium which helps prevent tooth decay.
One typical ejaculation contains 150 mg of protein, 11 mg of carbohydrates, 6 mg fat, 3 mg cholesterol, 7% US RDA potassium and 3% US RDA copper and zinc. The protein content is roughly equivalent to that found in one egg white. Also, women physically exposed to semen are less likely to suffer from depression. The ingesting of it is called 'spermophagia'. Studies suggest that seminal plasma both prevents and fights cancer, particularly breast cancer.