some practical issues such as the level of nontoxic beta-carotene which could maintain the reduced frequency of micronucleated cells and the remission of oral leukoplakias for prolonged periods of time , the logistics of distributing beta-carotene to the many millions of smokeless tobacco users who are at elevated risk for oral cancer , and the possibility of using beta-carotene in the form of sweet potatoes or red palm oil , which could contain an economical source of beta-carotene for developing countries in which most of the tobacco chewers live , still remain unresolved .
C0520511
distributing
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many