Are Synthetic Vitamins Actually Healthy?
Why I'm skipping prenatal vitamins for my second pregnancy
This post started out as a missive about my somewhat-controversial decision to not take prenatal vitamins for my second pregnancy (which I am now just past halfway through). But as I began to do the research to justify my decision, I learned way more than I expected and found myself in another rabbit hole about autism and other forms of “neurodivergence.”
Consequently, I’m splitting this post into two parts: this is the first, and concerns prenatal vitamins and synthetic vitamins in general; the second (“Down the Folic Acid Rabbit Hole”) is available here.
I’m not a medical professional, and this is not medical advice.
This post is too long for email and you’ll have a better reading experience if you click the title to read it online or in the Substack app.
Are Prenatal Vitamins Healthy / Necessary?
I found out I was pregnant near the end of a two-week trip to Mexico with my family. The week prior, I’d gone to a Mexican walk-in clinic with an odd rash that turned out to be a common fungal infection in the area; the doctor (quite reasonably) blamed the fact that I’d been chugging smoothies and drinking 1-2 beers per day while in Mexico, and that the increased sugar intake (which I’m not used to) and Mexican climate (which I’m not adapted to) caused the infection. He gave me some cream and a special soap to treat it, and a lecture about increasing my meat and vegetable intake and cutting down on the smoothies and beer. He also gave me a multivitamin, grumbling that while he couldn’t sit with me at meals to make sure I was eating properly, he could give me a multivitamin to ensure my nutritional needs were met.
Around the same time, it became clear my period wasn’t going to show up, and I started having overwhelming cravings for vegetables and avocados (likely because I was craving folate (Vitamin B9), one of the essential nutrients for a healthy pregnancy).
The day I took the pregnancy test, I sat on the restaurant patio of our hotel with my laptop while my daughter and husband played in the pool, and, on a whim, looked at the ingredients on my bottle of multivitamins.
I began to wonder how a bunch of synthetic nutrients, chemicals made in a lab and isolated from their context, compacted into a pill could be good for me.
And so I searched “prenatal vitamins” on Substack.
I found this post by Dr. Jen Gunter:
Dr. Gunter is an OB/GYN who likes to attack alternative and “natural” medicines, and, generally speaking, is not someone who is critical of Big Pharma or mainstream medical advice. I figured if she was criticizing prenatal vitamins, I should take her work very seriously. This is what I learned from her essay:
Many prenatal vitamins are contaminated with heavy metals and/or fungi, including lead, thallium, arsenic, cadmium, and mercury.
High doses of Vitamin A, Vitamin C, and Vitamin E can be harmful during pregnancy, and several prenatal vitamins contain higher than the recommended doses of one or more of these.
Many prenatal vitamins do not actually contain the amount of various nutrients that they claim to on their bottles (too little was more common than too much).
Vitamins that had been “verified” by a third-party were no better than those that hadn’t been.
Intrigued and alarmed, I did some Googling and learned:
In addition to most prenatal vitamins being contaminated with heavy metals, nearly half test positive for pesticides.
The heavy metals found in many brands of prenatal vitamins (lead, thallium, arsenic, cadmium, and mercury) are all linked to higher rates of autism spectrum disorder and other neurological complications.
Heavy metal toxicity, in particular from cadmium, may cause chronic magnesium deficiency. Symptoms of low magnesium include sleep issues, muscle soreness and cramps (including restless leg syndrome), fatigue, depression, anxiety, blood sugar imbalance, heart issues, and bone issues; these are strikingly similar to common pregnancy ailments.
Many prenatal vitamins contain petroleum-based synthetic food dyes and various filler ingredients (this seems pretty easy to avoid if you read your labels, however).
Prenatal vitamins may cause or worsen morning sickness in some women, with synthetic iron, choline, and iodine being the main culprits.
Excess intake of synthetic iron may be toxic, and synthetic iron can cause constipation, decreased appetite, and deficiencies in copper and Vitamin A.
Vitamin C helps us absorb iron; unfortunately, synthetic Vitamin C (ascorbic acid) and synthetic iron (ferrous salts) in combination can exacerbate oxidative stress in the gut, increasing the risk of ulcers, GI inflammatory diseases, and cancer.
Excess synthetic Vitamin C, which is manufactured from corn syrup and chemically treated, may cause DNA damage, impair the antioxidant system, and weaken mitochondria, affecting our ability to burn fat and sugar.
Synthetic choline (Vitamin B4) may increase the risk of blood clots.
Too much synthetic Vitamin A can cause birth defects and liver failure. In addition, “[s]ome researchers believe that synthetic vitamin A interferes with the proper utilization of natural vitamin A from foods.” While it’s widely believed that Vitamin A from food sources can cause toxicity as well—and consequently pregnant women are advised to avoid high-Vitamin A foods such as liver—it would be actually be extremely difficult / rare to consume enough from food sources (including liver) to cause toxicity.
Synthetic Vitamin E is derived from petroleum and is only around 12% as bioavailable as Vitamin E from food sources. Apparently, in supplements, even “natural” Vitamin E is anything but. In addition, “[e]xtra supplementation with vitamin E has not been shown to improve outcomes for either mothers or babies and may instead increase the risk of abdominal pain and premature rupture of the amniotic sack.” (This one’s fun because according to Dr. Gunter, the prenatal vitamins tested in the study had up to 332% times the amount of Vitamin E as stated on the labels).
What to learn more about how synthetic vitamins are made and what’s in them? Substacker
has the scoop (warning: it’s gross).
In addition to causing morning sickness, prenatal vitamins may also cause or contribute to the following (common!) symptoms in pregnant women:
Call me crazy, but these are supposed to be good for us?
Prenatal vitamins are a fairly new invention (1970s) and most women weren’t taking them until the late 1980s. This is interesting, because pretty much everything I’ve read indicates that children (and mothers!) have been getting less healthy since the 1980s, not healthier. Now, correlation is obviously not causation; there have been so many changes to our diets, lifestyles, environments, and culture since the 1980s, and it would be a mistake to chart the rise in consumption of synthetic vitamins (both in pill form and in “fortified” foods) against, say, the rise in rates of autism, allergies, or chronic illnesses and claim the former is “the” cause of the latter—however, at this point I’m certainly not convinced that prenatal vitamins or synthetic vitamins in general are doing us much good.
A 2016 study concluded that pregnant women do not need prenatal vitamins; the only supplementary nutrients that had any benefit were folic acid (synthetic folate) and Vitamin D3 (synthetic Vitamin D).
“[M]uch of the evidence for vitamin supplementation in pregnancy comes from studies carried out in low-income countries, where women are more likely to be undernourished or malnourished.”
My husband was at an event with a midwife and mentioned that I was writing about this topic, and she told him, confidentially and off-the-clock, that she did not think prenatal vitamins were necessary at all. (Similarly, none of the midwifes I’ve spoken to on-the-clock have seemed concerned when I told them I was skipping prenatal vitamins—especially after I told them my alternative nutritional plan, which I’ll get to at the end of this essay).1
The global market share for prenatal vitamins was around 0.68 billion USD in 2022 and is steadily climbing.
So at this point my Health Scam Alert! alarm is going off. But folate and Vitamin D are important, that checks out. It’s well known that insufficient folate can result in neural tube defects, and Vitamin D deficiency increases the risk of pre-eclampsia, gestational diabetes, preterm birth, bone deformity, and autism/ADHD.
I’d concluded a while ago that the best way to get enough Vitamin D was sunlight, egg yolks, fatty fish, and cod liver oil; I was already doing those things and figured I’d be fine without supplements. But I didn’t know that much about folate or folic acid, other than that it was important in pregnancy.
I will return to the topic of folic acid in part two of this essay.
The Consequences of Morning Sickness
Let’s hone in on two of the side effects of prenatal vitamins: morning sickness and lack of appetite.
In 2014, just over 18% of pregnant women in the US and Canada were prescribed an antiemetic drug for morning sickness. These drugs have all sorts of fun side effects. Past anti-nausea drugs famously caused severe issues such as congenital deformations and miscarriages.
It’s possible that morning sickness is an adaptive response to protect fetuses from toxins and fetus-deforming chemicals. Women who vomit have lower rates of miscarriage than women who experience nausea without vomiting.
If this is the case, that sort of suggests prenatal vitamins and synthetic vitamins in general are toxic if they cause morning sickness, doesn’t it?!
Salty and starchy snacks can cause stomach upset, but they can also help to lift your mood during the first trimester. You can eat potato chips, goldfish crackers, or butter toast bread as it will help you deal with morning sickness and hunger.
Women with morning sickness often struggle to eat, and are advised to eat bland, plain foods high in carbohydrates like bread, rice, crackers, and pasta. These foods are low in natural nutrition, and are often fortified with synthetic nutrients such as calcium, iron, and/or Vitamins B1, B3, B9 (folate), and B12. Many pregnant women end up eating a very poor diet in the first trimester (more carbohydrates, more processed foods, less protein and fat) because of morning sickness.
Ultra-processed foods such as goldfish crackers, pop tarts, and chips may be as addictive as smoking.
Eating lots of highly-processed foods may also cause an aversion to healthy, whole foods. In one interesting study by Paul Kenny, he found that rats who were fed a processed-food diet for a while, when the junk food was taken away and replaced with healthy food, rejected the healthy food. “The animals would rather starve themselves.”
Vitamin B1 is essential for glucose metabolism and nerve, muscle, and heart function. A Vitamin B1 deficiency can cause lack of appetite.2 Unfortunately, refined sugars and flours rapidly deplete Vitamin B1, and so consuming processed foods fortified with B1 that are also high in refined carbohydrates might not do a lot of good. Synthetic Vitamin B1 is “made from hydrochloric acid, acetone, ammonia, and coal tar to form thiamine hydrochloride or thiamine mononitrate” and is cheaply made in China.
Good natural sources of Vitamin B1? Pork, nuts, eggs, trout, and black beans. Unfortunately, meat, fish, and eggs are common food aversions during pregnancy.
Vitamin B6 is known to protect against morning sickness. However, synthetic B6 (pyridoxine hydrochloride) “is produced from formaldehyde, HCL acid, and petroleum ester, which are not easily converted to its usable form” and can cause peripheral neuropathy when taken in excess.
However, do you know what’s a great dietary source of Vitamin B6? Beef liver. (Which, again, contrary to popular opinion, is actually perfectly safe to consume in moderation while pregnant, especially if you are diligent about avoiding exposure to synthetic Vitamin A). As a bonus, beef liver is a decent source of Vitamin B1 too!
Which brings me to dietary alternatives to prenatal vitamins:
Finding Alternatives to Prenatal Vitamins
So if I wasn’t going to take prenatal vitamins, how would I ensure I got enough of the nutrition my baby and I needed?
After a bunch of research, I’d come up with the following plan:
Get sunlight on my bare skin whenever it’s available for 30+ minutes per day, without sunscreen (Vitamin D).
1-2 teaspoons of cod liver oil (without synthetic Vitamin A added!) every day (Vitamin A, Vitamin D, omega-3 fatty acids).
1 tablespoon blackstrap molasses each night before bed (iron, calcium, magnesium, potassium, phosphorus, manganese, copper, and Vitamin B2 and B6). Bonus: helps with pregnancy constipation and helps you sleep at night!
1 teaspoon moringa leaf powder each night before bed (calcium, potassium, zinc, magnesium, iron, copper, Vitamin A, Vitamins B3, B6, folate (B9), Vitamin D, Vitamin E). Bonus: lots of antioxidants! And according to a trend on social media, lots of models take it daily for healthy and sexy hair and skin.
2-3 organic, pastured eggs every morning for breakfast (Vitamins A, B2, B4 (choline), B5, B7, B9/folate, B12, D, and E, phosphorus, selenium, calcium, zinc, copper, omega-3 fatty acids, lutein, zeaxanthin, iodine).
Grass-fed butter every day (Vitamin A, Vitamin D, Vitamin E, Vitamin K2, omega-3 fatty acids)
3-4 Brazil nuts every day (copper, selenium, magnesium, manganese, phosphorus, zinc, Vitamin B1, Vitamin E).
Lots of fruits and vegetables, focussing on ones high in folate (e.g. avocado, banana, citrus fruits, broccoli). Obviously lots of nutrition here, in particular Vitamin C.
Eat beef liver pâté in small amounts at least 2-3 times per week (Vitamin A, Vitamins B1, B2, B3, B4 (choline), B5, B6, B7, B9 (folate), and B12, iron, copper, phosphorus, zinc, manganese, selenium, iodine, omega-3 fatty acids).
Eat some sort of fish, ideally wild salmon, at least once per week (omega-3 fatty acids, Vitamin A, Vitamin D, calcium, selenium, potassium).
If we get sushi3 (which we do a couple of times per month), always lots of seaweed salad for the iodine! Plus the occasional dried seaweed pack from Costco.
Eat steak or beef at least 1-2 times per week, especially grass-fed (omega-3 fatty acids, Vitamin A, Vitamins B3, B6, and B12, Vitamin E, selenium, zinc, phosphorus, iron, potassium, magnesium, copper). Avoid consuming dairy an hour before and six hours after eating red meat to improve iron absorption.
Other foods in regular rotation include homemade chicken soup, lots of herbs and spices, chamomile chai tea, dates, mixed nuts, 100% peanut butter, raw honey, hard cheeses, chia seeds, black sesame seeds, organic oats, and grass-fed, organic milk.
I was taking a magnesium bis-glycinate supplement and a myo-inositol (B8) supplement every day before finding out I was pregnant, and have continued to take both because I didn’t find obvious concerns with these two, unlike the various vitamins (inositol is not technically a vitamin), and because both of these are a bit more difficult to get enough of via diet.
Other than this, I’m trying to eat healthy in general, including avoiding refined sugars and processed foods and the usual stuff you aren’t supposed to have while pregnant. I’m being more intense about avoiding refined sugars and seed oils than in my first pregnancy, and while I was still using fluoride toothpaste in 2021 during my first pregnancy, I’ve since switched to a fluoride-free toothpaste. I’m still drinking coffee in the morning because it’s a vice I just can’t give up, but unlike the first time around I’m not drinking coffee out of take-out paper cups and avoiding the heavy metals and microplastics that apparently leach into hot drinks.
Now, I realize food prices have gone up dramatically over the past few years, and that many people cannot afford several of the healthy food items on my list. I believe this is a human rights issue and I don’t think anyone should feel bad for not being able to afford healthy food (I think you should be pissed at food corporations and Western governments!). Some items are also not readily available in certain locations.
But I have some good news! The two heavy-hitter items on my list—blackstrap molasses and beef liver—are cheap as heck! You can buy 675 grams of blackstrap molasses (45 tablespoons / days worth) and about 7-8 ounces of frozen beef liver (which lasts me about 10 days) for about $6 CAD each. The iron-rich molasses is definitely way cheaper than iron supplements, and it relieves constipation instead of causing it. Beef liver is basically a multivitamin that relieves nausea instead of causing it. All at a fraction of the price of pills!
Moringa leaf powder is also very inexpensive, especially if you’re only taking about a teaspoon per day. And you can get a pretty decent price on organic, pastured eggs, Brazil nuts, dates, peanut butter, and certain fruits and vegetables if you buy them at Costco. Cod liver oil isn’t too bad either, if you’re willing to buy it in liquid form instead of capsules (I use Nordic Naturals).
As for the sun, well, that one’s free :-)
So how’s it going?
Well, so far (I’m at 23 weeks), I’ve had zero pregnancy complications. Apparently I’m having a perfectly healthy pregnancy. Nutrient levels are good. I have significantly more energy and less brain fog than in my first pregnancy (even though I’m still breastfeeding my toddler). And I had far less morning sickness this time around; I know this is caused by the dietary differences because the handful of times I did eat something I shouldn’t, I got very sick and threw up the offending item.
At this point in my first pregnancy, I had chronic yeast infections and would have to take antibiotics twice for UTIs and once for bacterial vaginosis. I’ve only had mild yeast symptoms so far this time around. My first child, at this point, had also been diagnosed with an umbilical cord defect (single umbilical artery) and categorized as a “high-risk” pregnancy. This time? No known issues and still low-risk.
I had a chronic iron deficiency and restless leg syndrome in my first pregnancy. So far, no evidence of any deficiencies and my legs are pretty much fine.
I’ve only had one bad headache / migraine so far in this pregnancy (I had a handful with my first) and it cleared up 15-30 minutes after I ate some of that beef liver pâté (I’m guessing it was a B vitamin issue).
Of course, I’m only in the second trimester, and there’s plenty of time for issues to show up. Plus, I realize that everything can seem to be going fine and dandy and a child can still be born with complications and grow to have health issues. And, as with my first, a pregnancy can be a hot mess of complications and you can still have a healthy child (she came out blue and had to be resuscitated and spend four days in the NICU; she’s now doing well, hitting milestones on time or early, happy, confident, friendly, and doesn’t get sick very often or that severely). I know a woman who had hyperemesis gravidarum (constant nausea and vomiting) during her pregnancy and her little boy is totally fine. Our bodies are amazing.
But while I can’t be sure that skipping the synthetic prenatal vitamins and using food “supplements” instead is making a difference for my child, it definitely seems to be making a difference for me. Overall, this pregnancy has been a far less unpleasant experience than my first one.
Look, I’m not going to lie to people and claim that beef liver and blackstrap molasses are appetizing (I mean, ew?) but heck, I think it’s worth it if it means not feeling like crap for nine months.
One last thing—nutrient deficiencies are dangerous during pregnancy, and if you cannot get the nutrition you need from food, supplements, even synthetic ones, are preferable over deficiencies. As well, some prenatal vitamins are much better than others, and use more natural ingredients and avoid crappy ones and contaminants. I have no idea which brands are the best, however, and it seems like the whole market is pretty sketchy.
Part Two: “Down the Folic Acid Rabbit Hole”
Part Three: Healthy (and Tasty) Recipes for Pregnancy (etc!)
I get along pretty well with most healthcare workers, and frequently chat away to them about the problems with Western allopathic medicine and public health and various plant-based alternative remedies I’ve tried and how they work. A lot of healthcare workers love this and encourage me to keep talking, saying some variation of “I’m not allowed to tell patients stuff like this but I totally agree / believe you.”
A Vitamin B1 deficiency may be an underlying cause of many common eating disorders, including anorexia and ARFID (avoidant-restrictive food intake disorder). Common deficiencies associated with ARFID in particular include Vitamins A, D, B12, B1, B2, C, and K, and zinc, iron, and potassium. Many children and adults with ARFID consume diets high in “beige” foods, i.e. processed foods high in refined sugars and flours which deplete Vitamin B1. Alcoholism can also cause a B1 deficiency, resulting in loss of appetite.
There are only two places in the world where it’s safe to eat raw fish / sushi while pregnant; Japan and Vancouver, Canada. I live in Vancouver. If you also live in Vancouver, it’s totally safe to eat wild salmon sashimi from a good restaurant and I recommend it! If you live anywhere else, do not eat raw fish!
I have been wondering about supplements, too, lately. After several years of having odd neurological problems, I finally went to a neurologist. And I was diagnosed as having toxic levels of B6. It hard to find good info on B6 toxicity, but some articles I found seem to suggest that B6 found in supplements might have a worse effect than B6 sourced from food.
I found this post about skipping prenatal vitamins for the second pregnancy very eye-opening! It's amazing to see the research behind synthetic vitamins. Excellent work! 👏👏