Koliini

Koliini, known in English as choline, is a water-soluble nutrient that is essential for human health. It is not classified as an essential vitamin, but the body requires it for several key biological processes. Humans obtain choline from the diet, and the body also makes some amount endogenously, though production is often not enough to meet physiological needs.

Choline serves multiple major roles. It is a precursor for the neurotransmitter acetylcholine, which is important for muscle control, memory, and many autonomic functions. It is also a building block for phospholipids, notably phosphatidylcholine and sphingomyelin, which are essential components of cell membranes and lipoproteins. In addition, choline contributes to one-carbon metabolism as a source of methyl groups and supports liver function and lipid transport, which can influence liver health and cholesterol metabolism.

Dietary sources of choline include eggs, liver, meat, fish, milk, and some plant foods such as soy and cruciferous vegetables. Average intake varies by population, but many adults do not meet established adequate intake guidelines. Recommended intakes (adequate intake values) for adults are typically around 425 mg per day for women and 550 mg per day for men, with higher needs during pregnancy and lactation.

Deficiency of choline is uncommon but can contribute to liver dysfunction and muscle damage, and adequate choline intake is particularly important during pregnancy for fetal brain development. Excessive intake can cause adverse effects such as gastrointestinal discomfort and, at very high intakes, low blood pressure or a fishy body odor. The tolerable upper intake level for adults is commonly listed as 3.5 g per day.