Calcium Metabolism in Postmenopausal Osteoporotic Women is Determined by Dietary Calcium and Coffee Intake ,

Abstract

Eighty-five patients, age 48 to 77 y with postmenopausal crush fracture osteoporosis, were investigated using a 7-d combined calcium balance and 47Ca tracer-kinetic turnover method taking the dermal calcium loss into account. Individual dietary records were obtained based on a 4-d registration at home before hospital admission and on questioning by a dietitian. The following dietary constituents were estimated: energy content, protein, methionine, cysteine, calcium, phosphate, magnesium, coffee, fiber and vitamin C. All patients were served individual diets based on the dietary records during study. Dietary calcium was measured in duplicates of all the meals served. All urine and feces were collected and analyzed for calcium content. The 47Ca kinetic data were analyzed according to a modification of the expanding calcium pool model. The overall calcium balance correlated significantly to energy content (r = 0.31, P less than 0.005), protein (r = 0.22, P less than 0.05), calcium (r = 0.28, P less than 0.01), phosphate (r = 0.27, P less than 0.02) and coffee (r = -0.21, P less than 0.05). However, a multiple backward linear regression analysis disclosed that only calcium (rp = 0.38, P less than 0.0005) and coffee intake (rp = -0.25, P less than 0.05) significantly influenced calcium balance. The equation was: calcium balance (mmol/d) = 0.14 x (dietary calcium, mmol/d) - 0.0016 x (coffee intake, mL/d) - 3.62. A coffee intake in excess of 1000 mL could induce an extra calcium loss of 1.6 mmol calcium/d, whereas intakes of 1-2 cups of coffee per day would have little impact on calcium balance.

Choices for achieving adequate dietary calcium with a vegetarian diet

“…Although caffeine consumed in high amounts acutely increases urinary calcium (42), the effect on 24-h urinary calcium is negligible (43). The study by Berger-Lux et al (43) was a well-designed double-blind, placebo-controlled trial, in contrast with other reports that estimated caffeine consumption from food-composition tables.…”

Effect of decaffeination conditions on quality parameters of Kangra orthodox black tea

“…Caffeine, a central nervous system (CNS) stimulant in black tea is reported to exert relatively negative effects in humans, including hypersensitivity (Broadbent, 1999), insomnia (Hindmarch et al, 2000), human behaviors (Smith, 2002), miscarriages and birth defects (Giannelli, Doyle, Roman, Pelerin, & Hermon, 2003;Rasch, 2003). Adverse effects on cardiac vascular system and calcium absorption that results in osteoporosis (Hasling, Sondergaard, Charles, & Mosekilde, 1992;Heaney & Recker, 1982;Massey, Bergman, Wise, & Sherrard, 1989) have also been reported. These effects brought a new market for decaffeinated teas, both green or black, for those who did not want to ingest caffeine such as pregnant women, infants, and children , and those who have a relatively slow detoxification rate of caffeine (Heckman, Weil, & Mejia, 2010).…”

Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

“…With regards to bone metabolism, increased coffee consumption was documented to cause a negative shift in overall calcium balance, but was not related to bone turnover in postmenopausal women with fracture osteoporosis [6]. Furthermore, caffeine was observed to interact with the TT genetic variant of vitamin D receptor [7].…”