Calcium also plays a role in many other vital physiological activities, including blood clotting, nerve conduction, muscle contraction, regulation of enzyme activity, cell membrane function and blood pressure regulation. Because these activities are essential to life, the body utilizes complex regulatory systems to tightly control the amount of calcium in the blood, so that sufficient calcium is always available. As a result, when dietary intake of calcium is too low to maintain adequate blood levels of calcium, calcium stores are drawn out of the bones to maintain normal blood concentrations. If a person's diet does not supply adequate calcium, this situation can result in osteoporosis after many years.

For young girls going through the rapid growth spurts of puberty, getting calcium from dairy products, such as cheese, may be better for building bone than taking a calcium supplement, suggests a study published in the American Journal of Clinical Nutrition.(19)

At the conclusion of the study, girls getting their calcium from cheese had higher whole-body bone mineral density and cortical thickness of the tibia than girls given supplemental calcium + vitamin D, supplemental calcium alone, or placebo. While the researchers noted that differences in the rate at which different children naturally grow might account for some of the differences seen in bone mineral density, they concluded: "Increasing calcium intake by consuming cheese appears to be more beneficial for cortical bone mass accrual than the consumption of tablets containing a similar amount of calcium."( Cheng S, Lyytikainen A, Kroger H, Lamberg-Allardt C, Alen M, Koistinen A, Wang QJ, Suuriniemi M, Suominen H, Mahonen A, Nicholson PH, Ivaska KK, Korpela R, Ohlsson C, Vaananen KH, Tylavsky F. Effects of calcium, dairy product, and vitamin D supplementation on bone mass accrual and body composition in 10-12-y-old girls: a 2-y randomized trial. Am J Clin Nutr. 2005 Nov;82(5):1115-26. 2005. PMID:16280447. (19 )

adds a new point of protective data: eating more dairy actually decreases gout risk(20)

(Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med. 2004 Mar 11;350(11):1093-103. 2004. PMID:15014182. )