Choline is obtained from the diet and from the biosynthesis of phosphatidylcholine. Phosphatidylcholine is catalyzed by the enzyme phosphatidylethanolamine-N-methyltransferase (PEMT), which is induced by estrogen. Because they have lower estrogen concentrations, postmenopausal women are more susceptible to the risk of organ dysfunction in response to a low-choline diet. A common genetic polymorphism in the PEMT gene can also increase this risk.
Postmenopausal women with low estrogen levels are more susceptible to the risk of organ dysfunction if they do not have enough choline in their diet. One study showed that when deprived of choline in their diets, 73% of postmenopausal women given a placebo developed liver or muscle damage, but this was reduced to 17% if estrogen supplements were given. The study also noted young women should be supplied with more choline because pregnancy is a time when the body's demand for choline is highest. Choline is particularly used to support the fetus's developing nervous system.