As the saying goes, "To replenish vitamins, eat plenty of vegetables and fruits." But what exactly are vitamins? What roles do different types of vitamins play? Next, Wuhan Healthdream will take you through these essential nutrients.
Definition of Vitamin
Vitamins (life-sustaining elements) are a class of low-molecular-weight organic compounds essential for maintaining human health. They do not participate in cell structure formation or energy provision in the body; instead, their primary role is to take part in human biochemical reactions and regulate metabolic functions. The human body cannot synthesize vitamins on its own and must obtain them from food.
Categories of Vitamin
Water-Soluble Vitamins: Refer to a category of vitamins that are soluble in water but insoluble in non-polar organic solvents, including vitamin C and vitamin B. After entering the human body, water-soluble vitamins need to be dissolved in bodily fluids first for absorption. Therefore, they cannot be stored in large quantities in the body, and the excess will be excreted through urine.
Fat-Soluble Vitamins: Refer to a category of vitamins that are insoluble in water but soluble in fats and organic solvents, including four types: vitamin A, D, E and K. Fat-soluble vitamins need to be absorbed together with fats in the intestines, and can be stored in the liver and adipose tissues after absorption.
Five Common Types of Vitamins
Vitamin B: There are more than twelve types of B-complex vitamins, all of which are water-soluble. They can only remain in the body for several hours, so they must be supplemented daily. Common types include B1, B2, niacin, B5, B6, biotin, folic acid and B12. A shared characteristic of B-complex vitamins is that they help the body convert food into energy and maintain the normal functioning of the nervous system.
Vitamin C: Also known as ascorbic acid, it is a powerful antioxidant that protects body cells from free radical damage. It is also an essential nutrient for collagen synthesis.
Vitamin A: It is a fat-soluble vitamin. It has two forms of sources: one is retinol from animal-based foods, and the other is carotene from plant-based foods (which can be converted into vitamin A in the body). It is crucial for eye health. Vitamin A serves as the essential raw material for synthesizing rhodopsin-the light-sensitive substance in the retina.
Vitamin D: Known as the "sunshine vitamin", because the skin can synthesize it on its own when exposed to sunlight. The main function of vitamin D is to promote the absorption of calcium and phosphorus, thereby supporting the growth and calcification of bones and teeth.
Vitamin E: It is a fat-soluble vitamin and an important antioxidant in the body. It protects cell membranes from free radical damage, thereby delaying aging and maintaining cell health.