Vitamins and Nutrition

Antioxidants in skincare are ingredients that perform a specific protective function on skin - neutralizing harmful free radicals that cause oxidative damage and premature aging. While antioxidant describes a functional category rather than a single ingredient type, in cosmetic formulation it refers to ingredients based on what they DO on skin rather than their chemical classification.

Vitamin C is chemically known as ascorbic acid (C6H8O6). It is an essential nutrient for humans and acts as an antioxidant. Citric acid gives citrus fruits their sour taste but is not Vitamin C. Salicylic acid is used in acne treatments and aspirin synthesis. Tricarboxylic acid refers to the citric acid cycle, not a specific single acid.

Vitamin B1 (Thiamine) deficiency causes Beriberi, a disease characterized by nerve and muscle damage, cardiovascular problems, and edema. Beriberi was common in populations whose diet consisted mainly of polished rice.

Vitamin K is essential for the synthesis of prothrombin and other clotting factors in the liver. Without adequate Vitamin K, blood cannot clot properly. Dietary potassium is an electrolyte, protein builds tissue, and Vitamin E is an antioxidant - none are involved in the clotting cascade.

Folic acid (vitamin B9) is part of the water-soluble B-complex vitamin group. Water-soluble vitamins dissolve in water and excess amounts are excreted in urine rather than stored. In contrast, vitamins A (retinol), D (calciferol), and K (phylloquinone) are fat-soluble and require dietary fats for absorption and are stored in body tissues.

Rainwater contains trace amounts of Vitamin B12, which is produced by bacteria in the soil and atmosphere. The B12 gets incorporated into water droplets, though in very small quantities.

Calcium, Vitamin D, and Magnesium are all essential for bone health - Calcium provides structure, Vitamin D enables calcium absorption, and Magnesium supports bone mineralization. Vitamin A is important for vision and immune function but is NOT specifically required for strong bones; in fact, excessive Vitamin A can actually harm bones.

Apricots, watermelon, and tangerines all contain beta-carotene, which the body converts to Vitamin A. Apples, while nutritious and rich in fiber and Vitamin C, are NOT a significant source of Vitamin A or its precursors.

Vitamins are classified into two main categories based on solubility: fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex, C). Solid-soluble and liquid-soluble are not valid vitamin classifications.

Fat-soluble vitamins are A, D, E, and K. They dissolve in fats and are stored in the body's fatty tissues and liver. Options A (Vitamin A), B (Vitamin D), and D (Vitamin E) are all fat-soluble, while Vitamin C is water-soluble.

Vitamin K is found in leafy green vegetables, some vegetable oils, and to some extent in fish. While greens are the richest sources, fish does contain Vitamin K, making option D correct among the choices given.

Vitamin C (ascorbic acid) is abundantly found in citrus fruits like lemons and oranges. Both options A and B are correct sources. Wheat does not contain Vitamin C, and egg yolks are not a significant source of this vitamin.

Vitamin K is a fat-soluble vitamin, not water-soluble. Fat-soluble vitamins (A, D, E, K) dissolve in fats and can be stored in the body, while water-soluble vitamins (B-complex and C) dissolve in water and are not stored. The statement is false.