noun 다운로드 🔗공유 니아신 A water-soluble vitamin, a component of vitamin B complex, found in meat, yeast, and dairy products; it is essential to metabolism. Examples : "My grandmother takes niacin supplements to help with her energy levels. " 할머니는 에너지 수준을 돕기 위해 니아신 보충제를 복용합니다. medicine physiology food biochemistry substance biology chemistry AI와 채팅어휘 게임독해 연습