BGLAP and calcification: Natto is rich in vitamin K2 (menaquinone-7 [MK-7]), which contributes to the carboxylation of osteocalcin, a bone protein involved in bone formation, and to the prevention of arterial calcification.14 A study targeting Japanese people found that serum MK-7 levels were significantly higher in those who frequently consumed natto.15 The incidence of hip fractures in women tended to be lower in prefectures with higher per capita consumption of natto.15 These findings suggest that high MK-7 levels from natto consumption may contribute to lowering fracture risk in Japanese women.