Phosphorus is the second-most abundant mineral found in the body, after calcium. Although roughly 85 percent of all phosphorus in the body is found in the bones and teeth, phosphorus also plays important roles in all cells, particularly in muscles. A deficiency in phosphorus, which is called hypophosphatemia, can cause many symptoms, including fatigue. If you suspect you have a phosphorus deficiency, seek treatment from a medical professional.
Phosphorus is a key component of a molecule called adenosine triphosphate, or ATP, that serves as an energy source for almost all cells in the body. Adenosine triphosphate fuels numerous biochemical reactions and larger functions of the body, such as muscle contraction. When phosphorus levels are low in the body, cells cannot use ATP as an energy source. On a large scale, this means muscles do not have energy to contract, leading to muscle weakness and fatigue.
Low levels of phosphorus also have effects on the tiny scale of individual cells. When cells do not have enough ATP, they cannot fuel the essential biochemical reactions of life. One of the first effects of this lack of cellular energy is increased bursting of red blood cells, leading to anemia. Red blood cells transport oxygen from the lungs to the rest of the body, and when levels of red blood cells drop, the rest of the body cannot obtain enough oxygen, making fatigue worse. Anemia also causes symptoms of dizziness, confusion, fainting and a pale complexion.
Phosphorus deficiencies can cause several other symptoms in addition to fatigue, including impaired immune function, bone weakness, bone pain and arthritis. Damage to the nervous system also can occur, causing loss of balance and coordination, loss of reflexes, numbness, tremors and tingling. Loss of appetite and unintentional weight loss also can develop, as can irregular breathing and heartbeat, leading to abnormal readings on an electrocardiogram. In severe cases, paralysis and coma can result.
Causes of Deficiency
Lack of phosphorus in the diet is rarely the cause of a phosphorus deficiency because many foods contain phosphorus, including all grains, milk and all protein-rich foods. Another underlying health condition is usually the cause of a phosphorus deficiency, particularly conditions that disrupt nutrient absorption in the intestines, like celiac disease and Crohn's disease. Alcoholism, diabetes and starvation also are possible causes of low phosphorus levels.