Semen is a complex biological fluid that contains a mixture of sperm cells and various secretions from the male reproductive organs, primarily the seminal vesicles, prostate gland, and bulbourethral glands. Its nutritional composition is relatively minimal in terms of caloric and nutrient content, as it is primarily water with small amounts of sugars, proteins, and trace minerals. Here’s an approximate breakdown of its composition:
1. Water (90-95%)
- Semen is predominantly water, which acts as a medium to transport sperm and the other components.
2. Proteins and Amino Acids (1-2%)
- Proteins and enzymes in semen support sperm function and motility. Specific proteins include enzymes like proteases and other sperm-protective proteins.
- Amino Acids: Semen contains trace amounts of amino acids like glutamic acid and aspartic acid.
3. Fructose and Sugars (0.2-1%)
- Fructose: The primary sugar found in semen, supplied mainly by the seminal vesicles, providing energy for sperm.
- Other Sugars: Semen may contain small amounts of other sugars, such as glucose and inositol.
4. Minerals and Trace Elements (0.1-0.5%)
- Key minerals include zinc, calcium, magnesium, potassium, and phosphorus.
- Zinc: One of the most significant minerals in semen, it stabilizes sperm DNA and aids in sperm motility.
5. Lipids (0.2-0.5%)
- Semen has small amounts of lipids, including prostaglandins, which may influence sperm motility and function.
6. Hormones and Other Compounds (Trace amounts)
- Hormones: Contains trace amounts of testosterone, estrogen, and other steroids.
- Other Compounds: Includes a range of other biomolecules, such as neurotransmitters (like serotonin), citric acid, lactic acid, urea, and creatine.
Estimated Nutritional Breakdown per Ejaculate (Approximate)
While the values can vary, a typical ejaculate (around 3-5 mL) has about:
- 5-25 calories
- 200-500 mg of protein
- 11-15 mg of fructose
- 3-5 mg of zinc
Each component plays a role in maintaining sperm viability and supporting reproduction rather than providing substantial nutritional value.
