非常同意 要純化成單體會讓成本升高很多 仔細研究 PIC/S and Food GMP you will find that the pharmaceutical regulation(PIC/S) is much higher than that of food. USFDA 要求所有 impurity 物都分析API source need to have DMF...At least This so called "Natural Vitamine" need to show the SGS test reprot(COA, Certificate of analysis) for common pollutants.