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 <span class="TitlePageSM">化学式</span> </center>
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 <span class='duanluoBegin'>维生素A是一种脂溶性维生素，有机化合物，化学式是C<sub>20</sub>H<sub>30</sub>O，对热、酸、碱稳定，易被氧化，
 	紫外线可促进其氧化破坏。维生素A包括A1及A2，A1即视黄醇。维生素A2即3-脱氢视黄醇，其生理活性为维生素A1的40%。</span><br>
 <span class='duanluoBegin'> 胡萝卜中富含的维生素A1具有预防夜盲症、抗衰老和促进骨髓生长等功效。</span><br>
 
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