1. Andon MB, Peacock M, Kanerva RL, De Castro JAS (1996) Calcium absorption from apple and orange juice fortified with calcium citrate malate. J Am Coll Nutr 15:13–16
2. Heaney RP, Saville PD, Recker RR (1975) Calcium absorption as a function of calcium intake. J Lab Clin Med 85:881–890
3. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Food and Nutrition Board, Institute of Medicine (1997) Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. National Academy Press, Washington
4. Fatima M, Nawaz H, Kassi M, Rehman R, Baloch SN (2009) Determining the risk factors and prevalence of osteoporosis using quantitative ultrasonography in Pakistan adult women. Singapore Med J 50(1):20–28
5. Heaney RP, Recker RR, Hinders SM (1988) Variability of calcium absorption. Am J Clin Nutr 47:62–64