Prenatal Supplements: What’s in Your Prenatal Vitamin?
By Julia Rosen - The New York Times
When I told my doctor that I was thinking of getting pregnant a few years ago, she advised me to start taking a prenatal vitamin right away. So I stopped by the grocery store on my way home and made for the supplement aisle. As I studied the array of options before me, I quickly grew overwhelmed.
I noticed that different brands contained slightly different concoctions of ingredients, with wildly different amounts in each. Each multivitamin extolled its benefits, but also bore the familiar disclaimer that its claims had “not been evaluated by the Food and Drug Administration,” which I found unsettling. Who, I wondered, was looking out for pregnant people?
The answer turns out to be complicated. Like other dietary supplements in the United States, over-the-counter prenatal vitamins are not regulated like drugs and do not require F.D.A. approval before hitting shelves. As a result, their content and quality can vary, and what’s on the label doesn’t always match what’s in the bottle. Some prenatal vitamins, I later learned, even contain levels of contaminants that many experts find troubling.
“It’s a little disturbing,” said Rebecca Schmidt, a molecular epidemiologist at the University of California, Davis, who studies the effects of environmental exposures in pregnancy. “We recommend them to everyone and then we don’t really look at them.”
Dr. Schmidt said that the benefits of prenatal vitamins still outweigh any potential risks. But the burden of finding a safe and effective product often falls on prospective parents. In my case, I left the store empty-handed and spent hours at the computer mustering all of my journalistic and scientific training to find the best product. It was exhausting, and ultimately futile (more on that later). Mostly, I just remember thinking: It shouldn’t be this hard to follow doctors’ orders.
A regulatory gray area
Pregnancy tends to sap the body’s nutritional stores while also increasing its demands. So health providers in the United States usually advise expectant mothers to round out their diets with prenatal multivitamins. Ideally, these vitamins should contain key ingredients like folic acid to prevent neural tube defects, iodine for brain development and iron for blood supply. And ideally, they would provide these nutrients in the appropriate amounts — not too little or too much.
“There’s definitely a ‘Goldilocks’ area for each,” Dr. Schmidt said.
In reality, though, not all prenatal vitamins contain all of the recommended nutrients. Some omit iodine, for example, and most gummies lack iron. Ingredient amounts can also vary by an order of magnitude. The amount of vitamin B12 in the brands I considered ranged from 100 to 3,500 percent of the recommended daily value.
“They’re all over the place,” said Dr. Tod Cooperman, the president and founder of ConsumerLab.com, which conducts independent tests of supplements and other products. And that’s just what’s on the label; independent analyses show that some prenatal vitamins often contain much more or much less of certain nutrients than they claim.
Supplements occupy a regulatory gray area in the United States. By law, the industry must abide by the F.D.A.’s Current Good Manufacturing Practices, or C.G.M.P.s, which include requirements for producing, packaging and labeling supplements. But companies have wide latitude to decide what goes into their products. And they are largely expected to regulate themselves, said Ikhlas Khan, director of the National Center for Natural Products Research at the University of Mississippi. (The F.D.A. does investigate complaints, conduct inspections and regularly issues warnings.)
One particularly murky issue for prenatal vitamins involves contamination with heavy metals, especially lead. Researchers say that no amount of lead is safe to consume, and even low levels of exposure have been linked to low birth weight and decreased growth in infants, and reduced I.Q. and behavioral problems in children.
However, a 2008 F.D.A. analysis of 75 prenatal vitamins aimed at pregnant or lactating women found that all contained some amount of lead, with one brand registering nearly nine micrograms per serving. And in a 2018 study of 26 common prenatal brands found in retail stores in Canada, researchers measured lead levels ranging from 0.1 to 4 micrograms per daily dose. A recent survey of 220 prenatal vitamins by the Sinclair Broadcast Group and Ellipse Analytics reported that 25 contained more than 0.5 micrograms per serving.
Those in the supplement industry are quick to point out that we’re regularly exposed to heavy metals from our food, thanks to decades of air, water and soil pollution — which is how most contaminants get into vitamins. “A lot of this is a lack of consumer understanding about the ubiquity of lead,” said Steve Mister, the president and chief executive of the Council for Responsible Nutrition, a trade association. The industry’s goal, he said, “is to get it as low as possible.”
And indeed, all of the products tested in those studies and surveys fall below the F.D.A.’s Interim Reference Level of 12.5 micrograms of lead per day for women of childbearing age. The I.R.L. is designed to prevent a person’s blood lead level from rising to 5 micrograms per deciliter — the point at which the Centers for Disease Control and Prevention recommends clinical monitoring in children — and is set far below that threshold as a precaution, said an agency spokeswoman.
However, some researchers argue that the F.D.A.’s limit isn’t strict enough. Bruce Lanphear, a lead researcher at Simon Fraser University in Canada went so far as to declare it “probably just wrong.” Lanphear and other scientists consider California’s limit of 0.5 micrograms per day to be a more protective level for pregnant people, and less is even better — especially in a daily vitamin where there are concerns about cumulative exposure. Unfortunately, consumers have little information about exactly how much is in their pills.
In 2019, the city attorney of Los Angeles filed a complaint on behalf of Californians against the supplement maker Rainbow Light, which is owned by the Clorox Company. On its website, Rainbow Light advertised its vitamins as free of heavy metals. But the city attorney commissioned independent tests that revealed detectable levels of lead, arsenic and cadmium. Rainbow Light and its affiliates settled that case for $1.75 million, as well as a national case in 2020 for $6.75 million, brought by customers outside of California. (The companies did not admit wrongdoing.)
Erin Smid, the lead plaintiff on the national case, had taken the vitamins for nearly two years — from before she conceived through the birth of her twin boys. Only later did she hear the allegations that her pills contained lead. “I felt like I’d been tricked,” said Smid, 37, a former lawyer and full-time parent in Lake Forest, Ill. (She received her settlement check for $3,000 last fall.)
To be clear, lawyers did not claim that the amount of lead found in Rainbow Light’s products exceeded California’s limits. In a statement, company representatives said that a daily dose of their prenatal vitamins contained less lead than you’d get from a standard serving of spinach. But the case highlighted a disturbing irony: Rainbow Light only drew scrutiny because of potential false advertising, but consumers know even less about other companies that don’t make such bold claims.
Doctors and industry representatives, including Mister, recommended choosing vitamins that have been certified by trusted third-party groups. Organizations like N.S.F. International and U.S. Pharmacopeia grant seals of approval after conducting audits to ensure that supplement makers comply with C.G.M.P.s and that their products meet established specifications. ConsumerLab.com also offers certifications and provides independent product reviews to subscribers. (In 2019, C.V.S. announced that it will only carry products that have been tested by a third-party.)
Some newer testing companies offer more specific data. Labdoor provides detailed reports on vitamin composition and Pure Market evaluates purity, but does not give exact numbers, which makes the grades hard to judge.
Dr. Nathaniel DeNicola, a physician at Johns Hopkins Medicine who serves as the environmental health expert for the American College of Obstetricians and Gynecologists, said that women should start their vitamin search by asking their health care providers for recommendations and for help answering other regulatory and scientific questions. He recommended using third-party testing as “a final consideration among otherwise similar products.”
But that doesn’t mean the process will be easy. By the end of my search, I had given up on finding the best prenatal vitamin and was ready to settle for good enough. So I chose The Honest Co.’s “Prenatal Once Daily,” which got a “C-” from Labdoor (a middle-of-the-pack grade) but advertised itself as tested, certified and “ultra pure.” While researching this article, however, I discovered that the pill got an F from Pure Market. (The Honest Co. did not respond to questions about its scores or certification process.)
On top of that, I learned that medical authorities in Europe don’t recommend prenatal multivitamins at all. Instead, patients are advised to take folic acid before conception through the first trimester of pregnancy and to consider a vitamin D supplement in the third trimester. “In most countries, that’s it,” said Jacky Nizard, president of the European Board and College of Obstetrics and Gynaecology. “There are no guidelines for anything else.”
Even the World Health Organization has historically recommended folic acid and iron supplements over prenatal multivitamins for most pregnant people. (It only recently endorsed them, with caveats, and citing evidence of “limited benefit and little harm.”)
Given these global discrepancies, it’s no surprise that consumers here are confused. But ultimately, experts do agree on one thing, and that’s the importance of a healthy diet. Vitamins and fortified foods provide insurance that we get enough critical nutrients like folic acid. But like Dr. Nizard said, “If you eat properly, you should have everything else.”