Yuja, also known as citron, is a fruit commonly used in East Asian cuisine, particularly in Japanese and Korean dishes. Niacin, which is another name for vitamin B3, is a nutrient found in various foods, including Yuja.

Native to Asia, yuja is a citrus fruit that resembles a cross between a lemon and an orange. The fruit is small and spherical, with a thin, yellow-orange skin, and it has been used in Korean and Chinese medicine for centuries. 

Recently, yuja has gained popularity as an ingredient in skincare products. In this sense, this citrus fruit is full of oh-so-amazing vitamin C, having anti-inflammatory, antibacterial, brightening, and collagen-boosting properties that will make your complexion look glowy and healthy. In fact, it is often compared to lemons and oranges in terms of effectiveness!