Biochemistry of Vitamins

Organic compounds required in small amounts for normal health and growth. They are not synthesized by the human body and are essential for various metabolic processes.

Vitamins stored in the body's fat tissue, making them more likely to accumulate in excess.

Vitamins that dissolve in water and are not stored in the body in significant amounts.

A vitamin crucial for vision, cell growth, and immune function. Found in liver, dairy, and some fruits and vegetables.

The active form of vitamin A, involved in vision and cell growth.

Precursors of vitamin A found in plants, especially carrots, sweet potatoes, and spinach.

A deficiency of vitamin A, leading to night blindness and dry eyes, among other problems.

A severe form of vitamin A deficiency, characterized by dryness of the eyes, blindness, and potentially other health issues.

A photosensitive pigment found in rod cells of the retina, responsible for vision in dim light. Composed of 11-cis retinal and opsin.

A photosensitive pigment found in cone cells of the retina, responsible for color vision in bright light.

A form of vitamin A that acts as a hormone. It plays roles in cell growth, immune function, and reproductive health.

The precursor to vitamin D3, found in animal skin, converted to vitamin D3 by sunlight.

A plant-derived precursor to vitamin D2, present in foods like mushrooms.

The inability to see well in dim light, a symptom of vitamin A deficiency.

The term for a condition where the skin becomes rough and dry, a symptom of vitamin A deficiency.

The main storage site for Vitamin D in the body. This organ plays a crucial role in the activation process of Vitamin D.

An enzyme responsible for converting Vitamin D3 into its active form, calcitriol. This process occurs in the liver.

The active form of Vitamin D, also known as 1,25-dihydroxycholecalciferol. It's vital for calcium absorption and bone health.

A hormone that regulates blood calcium levels and stimulates the production of calcitriol. It's produced by the parathyroid glands.

The enzyme in the kidneys that converts 25-(OH)-D3 into its active form, calcitriol. Its activity is regulated by PTH and blood calcium levels.

Increased calcium absorption from the intestines, increased bone resorption, and increased calcium reabsorption in the kidneys. These processes are crucial for maintaining calcium homeostasis.

A condition that develops due to Vitamin D deficiency, characterized by soft and weak bones. It's more prevalent in children.

A condition caused by Vitamin D deficiency in adults, characterized by weak and brittle bones. This can lead to bone pain and fractures.

Vitamin E, also known as tocopherols, is a fat-soluble vitamin that acts as a potent antioxidant, protecting cells from damage caused by free radicals. It is crucial for healthy blood, muscles, and nerves.

Vitamin E is primarily obtained from various vegetable oils, such as wheat germ, cottonseed, olive, and coconut oils. Smaller amounts are present in liver, egg yolk, milk, and colostrum.

Vitamin K is a fat-soluble vitamin that plays a vital role in blood clotting and bone health.

Vitamin K1 is the major form of vitamin K found in plants, mainly in leafy green vegetables such as spinach, cauliflower, and cabbage.

Vitamin K2 is produced by bacteria in the gut. It's essential for bone health and plays a role in regulating blood calcium levels.

Vitamin K deficiency can lead to prolonged clotting times and hemorrhagic manifestations, particularly in the skin and mucous membranes.

Deficiency of vitamin K can occur due to various factors, including deficient gut bacteria (as seen in prolonged antibiotic use and newborns), fat malabsorption syndromes, liver diseases, and long-term use of anticoagulant drugs like dicumarol.

Although vitamin K is widely distributed in food and synthesized by bacteria in the large intestine, deficiency is uncommon due to its widespread availability.