Bone meal is produced from defatted, dried animal bones, usually cattle, which are ground into a fine powder and used as supplements or fertilizers. According to nutrition experts at Brigham and Women's Hospital, the approximate mineral content of a representative bone meal supplement, by percentage, is calcium, 31 percent; phosphorus, 13 percent; sodium, 6 percent; sulfur, 2.5 percent and magnesium, .33 percent. Other minerals present in much lower concentrations include copper, iodine, zinc, iron and manganese. Calcium, phosphorus and magnesium are the minerals of primary concern.
Calcium
Calcium is required for the development and maintenance of healthy bones and teeth. In its ionized form, calcium is essential for nerve conduction and muscle contraction. Dr. Elson Haas, author of "Staying Healthy with Nutrition," reports that calcium plays a role in some enzyme systems, such as choline acetylase, which helps to manufacture acetylcholine, an important neurotransmitter. Calcium is also instrumental in blood coagulation, where it activates a clotting factor called prothrombin.
Phosphorus
Like calcium, phosphorus participates in the structural integrity of bones and teeth. Elemental phosphorus is found in all cells, where it provides the backbone for adenosine triphosphate, a vital energy molecule. Phosphorus plays a role in the metabolism of carbohydrates and fats and in the synthesis of proteins, DNA and RNA. As a component of phospholipids, phosphorus helps to maintain cellular membranes and assists in the emulsification of fats in your tissues.
Magnesium
Even though magnesium is present in relatively low concentrations in your body, it is a physiologically important mineral. Magnesium helps to balance the activities of calcium in your nerves and muscles. Whereas calcium tends to be an stimulatory mineral, magnesium is a calming one. Magnesium is essential for the function of enzymes that are involved in carbohydrate metabolism, it helps to control the movement of fluids and nutrients across your cell membranes and it participates in transferring phosphate molecules during energy production.
Lead Contamination
Bone meal may seem like a natural way to get some calcium, phosphorus and magnesium into your diet. However, a 1993 study published in "American Journal of Public Health" revealed that approximately 25 percent of calcium supplements, including bone meal, contained more lead than is acceptable for children under the age of 6 and for pregnant women. A 2000 review in "The Journal of the American Medical Association" showed that lead contamination was a problem even in brand-name supplements.
BSE
A potentially more troubling problem stems from the 1995 discovery that routine rendering procedures do not eradicate the bovine spongiform encephalopathy agent, also known as BSE or "mad cow," from bone meal preparations. If you consume bone meal, make sure your supplement is certified "lead free," and ensure that your product originates in a country that is BSE-free. Follow the manufacturer's directions for dosage.
References
- Brigham and Women's Hospital: Bone Meal
- "Staying Healthy with Nutrition"; Elson M. Haas, M.D.; 2006
- "American Journal of Public Health"; Lead Content in 70 Brands of Dietary Calcium Supplements; B.P. Bourgoin, et al.; August 1993
- "The Journal of the American Medical Association"; Lead Content of Calcium Supplements; E.A. Ross, et al.; September 2000
- "The Veterinary Record"; Inactivation of the Bovine Encephalopathy Agent by Rendering Procedures; D.M. Taylor, et al.; December 1995
