Nitrogen is a chemical element with the symbol N and the atomic number of 7 and is vital to all life on earth. It is part of all amino acids, which make up proteins including those in DNA and RNA. The human body contains about 3% by weight of nitrogen, the fourth most abundant element in the body after oxygen, carbon and hydrogen. In respiration, the presence of nitrogen in the air inhibits oxidation of the lung tissues, where specialised cells extract the oxygen from the air (normally about 20% by volume).
Nitrogen is essential for the human body to synthesise amino acids. The protein that is consumed in the diet contains amino acids. These are made up of organic molecules containing nitrogen. Through the nitrogen obtained from these amino acids, the body produces other amino acids that are vital for body functions. Microbes transform nitrogen into forms that get absorbed in the plants.
Nitrogen is crucial for building and repairing tissues, producing enzymes and hormones, and maintaining overall bodily functions. It is also vital for the production of several nitrogenous compounds involved in a variety of functions such as hormones, immune mediators, neurotransmitters, antioxidant defences,
Nitrogen deficiency
A deficiency of nitrogen can lead to slow growth of the hair and nails, brittle hair and hair loss, slower wound healing, muscle wasting, bone fractures, sprains and complex injuries.
Nitrogen overdose
Excess of nitrogen in the body is harmful. If nitrogen intake exceeds nitrogen excretion, as can occur with high-protein diets, excess nitrogen leaves the body accompanied by calcium, increasing the risk for kidney stones and osteoporosis. Amino acids of protein are converted to ammonia by the liver. High levels of ammonia are toxic to the nervous system, with symptoms that include vomiting and tremors and can lead to coma and death. Therefore, moderate protein consumption is best.
NOTE: The recommended daily intake for protein for humans, from all sources, should never exceed the size of the clenched fist of the person consuming it and that includes children.
Highest sources of nitrogen in alphabetical order
Related subjects
- A-Z of minerals
- Bone and joint disorders
- Calcium
- Hair and nail disorders
- Kidney stones
- Osteoporosis