Calcium Phosphorus Ratio In Nutrition

Calcium and phosphorus are essential minerals, which means they must be acquired through your diet to ensure optimal health. According to the Linus Pauling Institute at Oregon State University, calcium is the most abundant mineral in your body. Phosphorus is the sixth most common element in your tissues. Each of these nutrients serves vital roles in your cells, and their absorption and elimination are linked. The dietary proportions of calcium and phosphorus have important implications for your overall well-being.

Functions

Most of your body's stores of calcium and phosphorus are found in your bones and teeth, where they serve as structural components and as mineral reservoirs for supplying your other bodily needs. A large number of enzymes require calcium or phosphorus to perform their functions, and both minerals are involved in cell signaling and regulation of hormone production. Calcium is instrumental in generating electrical "action potentials" that permit your nerves, muscles and heart to function normally. Phosphorus is required for cellular energy production and for maintaining a normal acid-base balance in your tissues.

Sources

Calcium is found in milk and other dairy products, green leafy vegetables, legumes, nuts, seeds and meats. Meats are good sources of phosphorus, as are milk, eggs, whole grains and wheat germ. Soft drinks are a significant phosphorus source for some people. Red meats, which make up a significant portion of many Americans' diets, furnish both minerals, but they contain far more phosphorus than calcium. Dr. Elson Haas, author of "Staying Healthy with Nutrition," states that the typical American diet provides too much phosphorus and not enough calcium, which diminishes your body stores of calcium.

Regulation

While your blood phosphorus level varies somewhat, your serum calcium level is tightly controlled to allow your cells to function normally. A slight fall in your calcium level stimulates the production of parathyroid hormone, or PTH, from your parathyroid glands. PTH stimulates the conversion of vitamin D to its active form in your kidneys, and vitamin D then stimulates the absorption of both calcium and phosphorus from your intestine. PTH also encourages your kidneys to retain calcium, but it stimulates urinary excretion of phosphorus. PTH's opposing actions in your kidneys help to "fine tune" your serum calcium concentration while partially compensating for the excess phosphorus in your diet. Phosphorus, however, is efficiently absorbed from your intestine -- up to 70 percent -- while you only absorb 30 to 50 percent of your dietary calcium.

Imbalance

Haas contends that the Western diet's excessive phosphorus content is largely responsible for America's high incidence of osteoporosis and other calcium-deficiency disorders, including some immune disorders, such as multiple sclerosis and Grave's disease. If you consume the same foods that most Americans do, your dietary phosphorus-to-calcium ratio may approach 5-to-1, which interferes with calcium absorption and leads to excess calcium removal from your bones. The ideal dietary calcium-to-phosphorus ratio is probably 1-to-1 or 1.5-to-1.

Considerations

People in developed countries typically consume too much phosphorus. Much of the phosphorus-calcium imbalance in your diet stems from the consumption of red meats, which supply up to 20-times more phosphorus than calcium, and soft drinks, which can contain 500 mg of phosphorus and virtually no calcium. Recommended dietary allowances for calcium vary from 210 mg daily for infants to 1,300 mg for growing children and adolescents, according to the Linus Pauling Institute. Recommendations for phosphorus range from 100 mg daily for infants to 1,250 mg for growing children and adolescents. Ask your doctor how you can achieve a healthier calcium-phosphorus balance.