细胞里色素量决定肤色深浅。北欧人日晒不足,细胞里色素少让阳光可以充分被利用产生维生素D。非洲人靠近赤道日晒又强又久,需要色素减少维生素D的产生。
细胞里色素量决定肤色深浅。北欧人日晒不足,细胞里色素少让阳光可以充分被利用产生维生素D。非洲人靠近赤道日晒又强又久,需要色素减少维生素D的产生。
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