liposolubles

Liposolubles are compounds that dissolve in fats or nonpolar solvents. In nutrition, the term most often refers to fat-soluble vitamins—A, D, E, and K—along with other lipophilic nutrients such as carotenoids that share similar solubility properties.

Absorption occurs in the small intestine and requires bile salts and pancreatic lipase to form micelles. The vitamins are packaged into chylomicrons and enter the lymphatic system before reaching the bloodstream. Because they are stored in the liver and adipose tissue, liposoluble micronutrients are not required daily in the diet and can accumulate over time.

Their storage makes them more prone to toxicity if consumed in excess, especially vitamins A and D. Excess intake can lead to hypervitaminosis with symptoms that vary by vitamin.

Deficiency is often due to fat malabsorption or very low-fat diets; symptoms include night blindness for vitamin A, rickets or osteomalacia for vitamin D, impaired antioxidant protection for vitamin E, and coagulopathy for vitamin K.

Dietary sources: vitamin A from liver, fatty fish, eggs and dairy; vitamin D from fatty fish and fortified foods; vitamin E from vegetable oils, nuts, and seeds; vitamin K from leafy greens; carotenoids from colorful fruits and vegetables, which provide vitamin A activity after conversion.