Choline
Most women are predisposed to an acetylcholine deficiency, because these symptoms set in with peri-menopause. Estrogen and testosterone stimulate the production of acetylcholine. As levels of those hormones decline, so does the production of this brain chemical. This prompts symptoms like memory lapses, dry skin and weight gain. The cholesterol in yolks help produce hormones levels. The reason why cholesterol levels go up after menopause is because your body is trying to produce more estrogen (which your ovaries are no longer releasing).