Effects of caffeine, vitamin D, and other nutrients on quantitative phalangeal bone ultrasound in postmenopausal women

OBJECTIVE: We investigated the controversial effects of coffee and other nutrients on bone mass. METHODS: In a study of 93 healthy postmenopausal women (mean ± standard deviation: 57.3 ± 7.1 y old and 8.9 ± 7.5 y since menopause) selected on the basis of not having changed their eating habits since premenopause, not smoking, not exercising, not receiving hormone-replacement therapy, and having a weight in the range of 70% to 130% of their ideal weights, amplitude-dependent speed of sound (Ad-SOS) was determined by quantitative bone ultrasound, and a prospective 7-d diet survey evaluated the intake of caffeine and nutrients involved in calcium metabolism. Women were stratified according to their caffeine, calcium, and vitamin D intakes and ratios of calcium to phosphorus and to protein. Ad-SOS differed only with vitamin D intake and was greater in the group taking at leasst 400 IU/d (P < 0.0001). RESULTS: In simple and multiple regression analyses, the only significant variable that affected Ad-SOS and nutrient intake was vitamin D (P < 0.0001). Phalangeal bone Ad-SOS was influenced only by the intake of vitamin D, not of caffeine or other nutrients. CONCLUSIONS: This lack of effect of caffeine and protein may be related to good nutritional intake or the low levels of caffeine consumed.