Table 5. Serum bone metabolism-related parameters by coffee intake in healthy adult males with below and above 75% of recommended calcium intakes.

Variables	< 75% of recommended Ca intake			≥ 75% of recommended Ca intake
	non-coffee (N = 39)	< 1 serving coffee a day (N = 87)	≥ 1 serving coffee a day (N = 33)	non-coffee (N = 51)	< 1 serving coffee a day (N = 92)	≥ 1 serving coffee a day (N = 28)
TALP, U/L	87.00 ± 22.77*	84.94 ± 1.13*	75.79 ± 14.63†	81.94 ± 17.23	77.48 ± 17.04	82.50 ± 20.07
OC, µg/L	24.48 ± 5.81	26.49 ± 22.34	22.81 ± 6.05	24.04 ± 8.05	23.41 ± 7.02	24.04 ± 6.55
1CTP, µg/L	4.86 ± 1.34	4.85 ± 8.95	4.49 ± 0.97	4.58 ± 1.22	4.52 ± 1.25	4.32 ± 0.85

Mean ± S.D.

TALP, total alkaline phosphatase; OC, N-mid osteocalcin; 1CTP, Type 1 collagen C-terminal telopeptide.

^*,†Values with different superscripts within a row are significantly different at p < 0.05 as determined by Duncan's multiple range test.