Abstract The effects of the bone and lipid metabolism were investigated in rats administered the diets prepared from cuttlefish shells (C-Ca), bonito viscera extract (VD) and bonito fish oil docosahexaenoic acid (DHA) from the viewpoint of the utility of marine resources. Six-week old male Wistar rats after being provided with the standard diet (AIN-93G) for 10 days were distributed into 7 groups (AG) and fed by each diet for about 5 weeks. A:standard diet; Bxontrol diet (Ca,VD and DHA had been removed from the standard diet); Ccontrol diet+Ca; Dxontrol diet+ C-Ca; E:control diet +C-Ca+VD, Groups A to E were administered with soybean oil. F:control diet +Ca+DHA; G:control diet+Ca+VD+DHA. The lipid metabolism markers (TG, PL and T-Cho) in the plasma were lower for F and G. Regarding the effect of the addition of vitamin D on the soybean 0il administered groups (A, C) and the DHA administered groups (F, G), there was no significant difference between C and F, but A and G had significant differences (p<0.05) in the Ca content in the femoral bone. In the bone metabolism the total BMD in the metaphysis region were 1.51, 1.51, 1.65, 1.53 and 1.60 times higher in C, D, E, F and G than B, respectively. These results revealed that the trabecular BMD level is maintained by the addition of DHA, the total and cortical BMD levels are maintained by the addition of vitamin D and the whole BMD is maintained by taking cuttlefish calcium together with vitamin D.