Choline: Some studies link low choline levels to increased risk of neural tube defects. Recommended levels have been established for this nutrient, but it's easy to get enough in your diet. Eggs are an excellent source of choline, for example. “Eating a few eggs a week should give you all you need,” Frechman says. “Most people can eat the equivalent of an egg a day without worrying about cholesterol.” Other choline-rich food sources include milks, liver, and peanuts.

Fluids: Fluid needs increase as women age. The reason: Kidneys become less efficient at removing toxins. “Drinking more fluids helps kidneys do their job,” Schwartz says. “Unfortunately, thirst signals often become impaired with age, so people are less likely to drink enough water and other fluids.” Rather than fret about how many glasses to drink, Frechman says, check the color of your urine. "It should be clear or very pale colored. If it becomes darker, you need more fluid.”