Vitamin A, also known as retinol, is derived from carotene compounds present in foods like egg yolk, butter, and cream. These compounds are converted into vitamin A by the body over time. A variant of vitamin A, called retinal, plays a crucial role in the eye by helping to transmit light sensations. A lack of vitamin A can result in various deficiencies.The term "vitamin" was first introduced in 1911 by Casimir Funk, a biochemist originally from Warsaw (1884-1967). While working at the Lister Institute in London, Funk discovered a substance that prevented neuritis in chickens that were otherwise lacking it in their diet. He named it "vitamine," reflecting its vital role in life and its chemical nature as an amine. The final "e" was later dropped when it was found that not all vitamins are amines. Vitamins were named in the order of their discovery, such as A, B, and C, except for vitamin K, which was named for "Koagulation" by Danish researcher Henrik Dam.Beta carotene, a powerful antioxidant, protects cells from oxidative damage that can lead to cancer. It is converted into vitamin A as needed. This compound is abundant in vegetables like carrots, sweet potatoes, and other leafy greens, as well as fruits like cantaloupes and apricots. Consuming excessive carotene can cause a temporary yellowing of the skin, known as carotenemia, often observed in infants who eat a lot of pureed carrots.Vitamin B1, or thiamin, supports enzyme functions in the body. A deficiency can cause beriberi, affecting the heart and nervous system.Vitamin B2 is essential for coenzyme reactions and a lack of it leads to inflammation of the mouth lining and skin.Vitamin B3 is a vital component of coenzymes involved in body metabolism. Deficiency can result in skin inflammation, oral lesions, and cognitive decline.Vitamin B6 acts as a cofactor for enzymes, and its deficiency causes skin and mouth inflammation, nausea, vomiting, dizziness, weakness, and other symptoms.Folate (folic acid) is crucial for synthesizing nucleic acids, which are the building blocks of genetic material. A lack of folate results in megaloblastic anemia.Vitamin B12 is essential for nucleic acid synthesis in all cells. Its deficiency can also cause megaloblastic anemia.Vitamin C plays a significant role in producing collagen, the structural protein in body tissues. A deficiency leads to scurvy, characterized by fragile blood vessels, poor wound healing, and bone deformities in children.Vitamin D is vital for the absorption and metabolism of calcium and phosphorus. Under normal sunlight exposure, dietary supplements are unnecessary as sunlight promotes sufficient synthesis of this vitamin in the skin. A deficiency can cause osteomalacia in adults and rickets in children.Vitamin E deficiency can lead to anemia.Vitamin K is crucial for the formation of blood clotting factors. A lack of vitamin K can cause abnormal bleeding.
