Adequate calcium is so essential for life that your body will resort to breaking down bone in order to ensure that it has normal amounts of this vital mineral. Not only does calcium promote strong bones, it also supports muscular activity and transmission of nerve impulses. Excess amounts of calcium, however, can negatively impact body function and lead to harmful calcium deposits.
How Calcification Occurs
About 99 percent of the calcium in your body resides in your bones. The remainder circulates in your bloodstream and supports a variety of essential life functions such as nerve impulse transmission. A hormone called the parathyroid hormone (PTH) regulates calcium concentration in your body. The more calcium that circulates in the blood, the greater the risk that calcium deposits or calcification will happen. It can occur on valves, within the arteries or soft tissue such as the brain. Calcium deposits may also cause kidney stones.
Dietary Calcium versus Supplements
Scientific evidence continues to emerge that the form of calcium you consume may influence calcification in your body. Calcium, of course, is essential for strong bones and teeth. Calcium intake is of special concern to women and the increased risk of osteoporosis of this population group. A study by the Harvard School of Public Health, published in the April 1997 issue of the “Annals of Internal Medicine,” found that high intake of dietary calcium decreased the risk for kidney stones. However, calcium supplements increased the risk. Researchers suggested that the inhibition of absorption of dietary oxalate, another substance found in foods, reduced kidney stone formation.
Hypercalciuria
Kidney stones or other signs of calcium deposits are rarely caused by diet. Rather, an underlying cause such as kidney disease affects the occurrence. A study by the Hospital de Clínicas de Porto Alegre in Brazil, published in the August 2011 issue of “Nature Reviews,” explains that vascular calcification is common in individuals with chronic kidney disease. The kidneys reabsorb calcium. An individual with kidney disease has high levels of urinary calcium, a condition known as hypercalciuria. The high concentration of circulating calcium provides the source for calcification of tissues.
Calcium Intake
To minimize your risk of calcification, you should stay within the recommended daily allowance for calcium. Adult men and women should get 1,000 mg per day. The RDA increases to 1,200 mg for women over 50 and men over 70. Dietary sources such as dairy products and fortified cereals are preferable to supplements if just for the additional nutrients they will provide. Salmon, for example, provides an excellent source of omega-3 fatty acids in addition to calcium. Until research uncovers the precise mechanisms for calcification, your diet should be your primary source of calcium.
References
- Linus Pauling Institute; Calcium; Victoria J. Drake; October 2007
- "Principles of Anatomy and Physiology"; G. Tortora et al; 2005
- “Annals of Internal Medicine"; Comparison of Dietary Calcium with Supplemental Calcium and Other Nutrients as Factors Affecting the Risk for Kidney Stones in Women; G. Curhan, et al.; April 1997
- Office of Dietary Supplements: Calcium
- “Nature Reviews"; Noninvasive Imaging for Assessment of Calcification in Chronic Kidney Disease; C. Karohl, et al.; August 2011
- "Journal of the American Society of Nephrology"; Genetic Hypercalciuria; O. Moe and O. Bonny; March 2005
