Koliinia

Koliinia, in Polish often referred to as choline, is a water-soluble essential nutrient and a quaternary ammonium compound. It is a key component of cell membranes through phosphatidylcholine and serves as a precursor to acetylcholine, a neurotransmitter, and to betaine, a methyl donor involved in homocysteine metabolism.

Biological role and importance. Choline supports liver function, normal brain development, and nerve function. Its role in methyl group metabolism links it to DNA and protein methylation reactions, while its inclusion in membrane phospholipids helps maintain cell integrity and signaling.

Dietary sources. Rich sources include egg yolks, liver, and other organ meats, as well as meat, fish, and dairy products. Plant-based sources such as soybeans, legumes, cruciferous vegetables, and whole grains also provide usable amounts of choline, though the content and bioavailability can vary.

Metabolism and utilization. After absorption in the small intestine, choline is delivered to the liver where it can be used directly or oxidized to betaine. It is also phosphorylated and incorporated into phosphatidylcholine via the CDP-choline pathway, contributing to membrane synthesis and lipid transport.

Deficiency and recommendations. Deficiency is uncommon in well-balanced diets but can contribute to fatty liver, muscle damage, and, in pregnancy, impaired fetal development. Adequate intake values vary by age and sex; for adults, AI is about 425 mg/day for women and 550 mg/day for men, with higher amounts recommended during pregnancy (about 450 mg/day) and lactation (about 550 mg/day).

Safety. Very high intakes may cause adverse effects such as hypotension, sweating, and a fishy body odor due to trimethylamine production. An upper intake level is generally considered around 3,500 mg/day for adults.