On Nutrition

A few weeks ago, I wrote about how your grandparents’ diet and environment affects your health today. One important detail in this discussion is critical developmental windows — times during our growth and development when what we are exposed to has major influence. One such window is the 1,000 days from the moment of conception to a child’s second birthday, which means that for women who intend to start a family, paying attention to nutrition before becoming pregnant is important.

Unfortunately, what passes for family planning in this country has more to do with avoiding unwanted pregnancies than planning for wanted pregnancies. I talked to registered dietitian Judy Simon, M.S., R.D., C.D.,  who teaches maternal and infant nutrition in the University of Washington’s nutritional sciences program and has a clinical practice specializing in fertility and pregnancy nutrition.

“Preconception nutrition is not prioritized enough, especially because 50 percent of pregnancies are not planned, and many women don’t know they are pregnant until well into their first trimester,” she said. “Those first 1,000 days are so important, but going back further into the preconception period is also important.”

Nutrients of note

It’s important for women to get adequate choline, folic acid and iodine to help prevent birth defects, including defects in the neural tube, the embryo’s precursor to the spinal cord and brain. If cells don’t have the nutrients needed to divide and multiply fast enough to form a closed, intact neural tube, traumatic birth defects can develop. This process wraps up around day 21 of pregnancy, before most women know they are pregnant.

“Food fortification and encouragement to take prenatal vitamins have reduced cases of neural tube defects, but that has leveled off,” Simon said. She said new public-health initiatives include fortifying masa flour from corn with folic acid to help reduce neural tube defects among Latina women.

Entering pregnancy with adequate iron is also important, as the body’s need for iron almost doubles during pregnancy to support rapidly expanding blood volume and tissue growth. This makes it easy for a woman to develop iron-deficiency anemia during pregnancy — it’s the most common nutrition-related complication of pregnancy — which increases the risk of preterm birth. Entering pregnancy with low iron will make it very difficult to get caught up, and some women will need iron supplements in addition to eating iron-rich foods.


Simon points out that there’s not a lot of standardization in prenatal supplements, and that more expensive supplements don’t guarantee better quality. “Really, supplementation is a small part of the picture. The food they eat and the environment they live in are more important.”

This has benefits for cognitive development, mental health and physical health, including reducing the risk of developing chronic diseases in adulthood. “When we talk about our genes, that may be only 25 percent of the picture,” Simon said. Epigenetics — changes in gene expression — may be the other 75 percent.

The perils of extreme diets

Restrictive diets are trendy, with many people avoiding entire food groups or entire macronutrients, such as carbohydrates. “When people go on extreme diets for health reasons, they may be doing more harm than good, when you look at the importance of the 1,000 days,” Simon said.

In fact, a 2018 study found that women who followed a low-carb diet during pregnancy had an increased risk of having a baby with neural tube defects. Why? Folic acid intake in women who limited carbs was less than half that of women who didn’t restrict intake of carbs. Since 1998, the Food and Drug Administration has required that folic acid be added to enriched-grain products like bread, pasta, rice and cereal.

And the value of a balanced diet goes beyond pregnancy.

“Parents need to model a variety of foods — maybe you’re not crazy about vegetables, but this is a good time to try new things,” Simon said.

The importance of early education

Simon said the ideal time for a woman to get her nutrition in order is three to six months before trying to conceive. That’s one reason she would like to see preconception nutrition addressed with all women of reproductive age, even if they are years away from considering becoming pregnant. Simon asks her younger female patients if they plan to start a family eventually and if they would like to start talking about optimizing nutrition for fertility and preconception.


This includes teens — why not educate about pregnancy prevention while also providing education about what to think about if they eventually decide to start a family? Simon points out that while the rate of teen pregnancy has decreased significantly, teen pregnancies do still happen, and the nutritional needs during pregnancy are much higher at that age.

“It’s also important to help women improve their nutrition between pregnancies,” Simon said. The optimal spacing between pregnancies is 18 months, enough time for women to replenish their nutritional stores, but many women have pregnancies that are closer together, whether planned or unplanned.

And if you think preconception nutrition only applies to women, you would be wrong. Men should also think about laying a good foundation for their future children, Simon said, as some chronic diseases can affect men’s fertility as well as their sperm quality. “Their sperm is really a reflection of their health,” she said.

Spreading the word

Simon said she’s excited that more areas of medicine, including fertility medicine, are embracing the importance of preconception nutrition and health care. “The attitude is, ‘Let’s not just help these couples get pregnant, lets help them have healthy babies that become healthy adults.’”

She said while the idea that what you eat now can affect your child’s health as an adult — and your grandchildren’s health — could feel daunting, it’s actually very positive.

“Everyone wants the best for their child. All the great things you are doing now are going to help your child and your grandchildren.”