单项选择题
A.400μg DFE/天B.600μg DFE/天C.800μg DFE/天D.1000μg DFE/天
A.50mgB.75mgC.100mgD.200mg
A.参与视网膜的光化学反应B.促进小肠黏膜对钙的吸收C.促进骨组织的钙化D.促进肾小管对钙、磷的重吸收