vitamins

Classification of Vitamins

fat-soluble and water-soluble.

Fat-Soluble Vitamins

Include A, D, E, and K; they are hydrophobic and absorbed with lipids.

Absorption of Fat-Soluble Vitamins

Fat-soluble vitamins require micelles and chylomicrons for absorption.

Storage of Fat-Soluble Vitamins

Stored in the body with lipids, primarily in the liver and adipose tissues.

Daily Supplementation Needs for Fat-Soluble Vitamins

Storage allows for skipping daily supplementation.

Vitamin A Sources

Found as active retinol and provitamin A (beta-carotene) in plants.

Beta-Carotene

Converted to retinol in the body and is sensitive to light, heat, and handling.

Vitamin A Functions

Essential for growth and development of tissues, especially during pregnancy.

Vitamin D Forms

Includes D3 (produced in animals) and D2 (produced in plants).

Vitamin D Synthesis

Vitamin D3 is synthesized in the skin from 7-dehydrocholesterol upon UVB light exposure.

Vitamin D Activation

Converted to its active form in the liver and kidneys.

Calcium Absorption

Vitamin D enhances calcium absorption from the intestine and kidneys.

Vitamin E Function

Acts as a powerful antioxidant that protects cells from oxidative damage.

Vitamin K Function

Promotes blood clotting by enhancing the conversion of prothrombin to thrombin.

Water-Soluble Vitamins

Include the B complex and C vitamins.

Absorption of Water-Soluble Vitamins

Hydrophilic and absorbed by dissolving in water in the blood.

Excretion of Water-Soluble Vitamins

Excreted in urine on a daily basis, they are not stored in significant amounts.

Daily Consumption of Water-Soluble Vitamins

Generally required due to lack of storage.

Vitamin C Sources

Found in citrus fruits, strawberries, kale, and broccoli.

Synthesis of Vitamin C

Humans cannot synthesize vitamin C and must obtain it from the diet.

Vitamin C Functions

Powerful antioxidant, important for collagen and carnitine synthesis.

Deficiency of Vitamin C

Can lead to scurvy.

Vitamin B Complex

Includes B1 (thiamine) and B3 (niacin), functioning as cofactors for enzymes.

Energy Metabolism

B vitamins are particularly involved in energy metabolism (ATP production).

Reabsorption of Calcium

Vitamin D regulates blood calcium levels by promoting reabsorption in the kidneys.

Oxidative Damage Protection

Vitamin E donates electrons to combat oxidative damage caused by free radicals.

Blood Clotting Enhancement by Vitamin K

Vitamin K enhances the conversion of prothrombin to thrombin for blood clotting.

Beta-Carotene Sensitivity

Beta-carotene is sensitive to sunlight, high temperatures, and handling.

Carnitine and Vitamin C

Vitamin C is essential for carnitine synthesis, aiding fat burning.

Essentiality of Vitamin C

Essential nutrient for humans, primates, and guinea pigs.

Collagen Synthesis

Vitamin C is important for synthesizing collagen in connective tissues.

B Vitamins Role in Enzymes

B vitamins serve as cofactors for enzymes in various metabolic processes.

Hydrophilic Vitamins

Water-soluble vitamins are hydrophilic and require water for absorption.