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Healthy Balance

Prenatal Vitamins: When, Why and How

Multivitamins aren’t usually necessary, according to a UVA pharmacist. But if you’re thinking about getting pregnant, it’s a different story.

Women need extra calcium and vitamin D when pregnant, according to Mark Lepsch, MD. Infants in the womb “take what they need. Women’s calcium stores can drop significantly during pregnancy.”

What’s the big deal? Can’t a woman just drink a lot of milk or eat yogurt to build calcium back up after the baby is born?

Taking prenatal vitamins before you're pregnant is more beneficial than you'd think.
Taking prenatal vitamins before you’re pregnant is more beneficial than you’d think.

It’s not that easy. “Bone density peaks at age 30, decreasing afterwards,” explains Lepsch. It’s not something you necessarily replenish. And of course, a lack of bone density leads to osteoporosis.

Why the vitamin D? It absorbs calcium. “If you don’t take it, calcium isn’t absorbed in your body.”

And then there’s iron. As a pregnant woman’s body develops the placenta, she adds “50 percent more blood volume; if you don’t make any more red blood cells, you can become anemic.” Anemia, while extremely common in pregnancy, can result in undesirable exhaustion.

Build Up Your Stores

You may wonder why getting pregnant can deplete a woman to such extremes. The problem isn’t pregnancy in itself so much as what’s there to start with. Which is why you want to start taking prenatal vitamins even before you get pregnant.

“It takes time, if you’re low, to build up your stores. It takes months. It’s not like you can say, ‘I’m low in this’ and you take it and it replenishes your body. If you have heavy menstrual periods, for instance, and low feratin iron stores, it’s going to be a month or so into your pregnancy until your body builds up the blood supply.”

The baby will need extra blood volume and calcium, so taking iron, calcium and vitamin D on a regular basis ahead of pregnancy stocks your body with the resources you need to stay healthy.


Check out our Maternity Monday series for more info on conception, pregnancy, childbirth and postpartum.

Folic Acid

But taking prenatal vitamins isn’t just a measure to maintain the mother’s health.

Studies show that folic acid helps prevent neural tube defects, like spina bifida. Again, the ideal time to start taking extra folic acid is a few months before pregnancy. The first eight weeks or first trimester is the crucial period when all the baby’s organs develop – called organogenesis – and you need folic acid built up in your body to provide for the fetus during that time.

This is also why, Lepsch explains, “alcohol and smoking have their worst effects during the first eight weeks — that’s when the baby’s trying to form its lungs, etc. “

What About Morning Sickness?

There’s yet another reason to start taking prenatal vitamins before you’re pregnant.

Morning sickness.

A quick poll of mothers I know showed the one problem they all shared was taking a prenatal vitamin and keeping it down while having morning sickness — some women experience nausea throughout their whole pregnancy.

Again, the vitamins you need during the crucial first trimester come from stores built up in your body over time, not from a daily pill. “That way, if you get sick later, there’s enough in your body already,” advises Lepsch.

He adds, “The most important thing is nutrition and drinking fluids. You do the best you can.”

Some points to remember if your prenatal vitamins are making you sick:

  • Never, ever take them on an empty stomach.
  • It doesn’t matter what time of day you take them, so if you’re getting nauseous in the morning, try taking them at night.
  • Try chewable children’s vitamins; that will be more helpful than taking nothing. They don’t have as much in them, so you can even take two.
  • If the vitamin is making you sick, you might have to stop taking it.

If You Can’t Take Prenatal Vitamins?

Don’t be too discouraged. Lepsch has some comforting information if it turns out you can’t take prenatals.

1. You’re probably okay: “In this country, all our foods are fortified. It is very hard to be deficient in vitamins in this country.” We need extra vitamin D in part because of sunscreen and spending less time in the sun, and we need calcium because we’re living longer and therefore at risk of more bone fractures.

2. There’s more to you and your baby’s health than vitamins: “A healthy diet and regular exercise are probably still the most important factors in determining your health and your baby’s health. ”

Another great way to prepare for a healthy pregnancy: Get a checkup.

Need a doctor? You can find a UVA doctor or primary care provider at numerous locations in the region.

Did you have problems taking prenatal vitamins? What did you do? Tell us in the comments below.

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