yī / shēng / jiàn / yì / tā / fú / yòng / yān / suān / lái / gǎi / shàn / xuè / yè / zhōng / de / dǎn / gù / chún / shuǐ / píng医生建议他服用烟酸来改善血液中的胆固醇水平。The doctor recommended that he take niacin to improve his blood cholesterol levels.