Vitamins are essential to human body, and 13 vitamins have been identified and classified as fat-soluble vitamins (A, E, D, and K) and water-soluble vitamins (B-group vitamins and vitamin C) according to their solubility (Turner & Mathiasson, 2000). In particular, fat-soluble vitamins are necessary for regulating various cell metabolisms, which include anti-oxidation, cell signaling, and the modulation of the immune system (Chadare et al., 2019; Turner, King, & Mathiasson, 2001). Vitamin A and its precursor, which is β-carotene, are predominantly found in plants, and they are mainly necessary for protecting the retina as well as scavenging free radicals (Akhtar
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