My friend Kaitlin (not my daughter, it should be noted.. we call this Kaitlin my Other Kaitlin..) over at The Bypassed Life wrote a great post about Flintstones vitamins in a way that makes it very easy to see why they are not a good choice for .. well?  Anyone.

She’s got some great content on her blog, including a post about a study on antidepressant absorption (or lack thereof) in our guts.  She’s worth a read if you are need of another good quality blog.

So without further ado:

What’s the Fuss about Flintstones?

Many years ago, the gold standard for post-operative supplementation was Flintstones children’s chewable vitamins, as well as Tums for calcium. Unfortunately, this regimen was woefully incomplete. Without the proper supplements, people developed deficiencies. Not always immediately—the body has stores of many vitamins—but they did eventually appear. In some people, circumstances helped to accelerate nutrient depletion. My friend Andrea had babies. Greedy little (adorable) things that they were, those babies stole from her vitamin stores. Her Flintstones and Tums simply couldn’t keep up. Andrea got rickets.

These cautionary tales are everywhere in the weight loss surgery world. There are countless post-ops five, ten, or more years out who have dug themselves out from deficiencies that were caused, at least in part, by bad medical advice. Despite these stories and the giant strides that have been made in bariatric and nutritional research, the recommendations given by surgeons are still outdated.

Flintstones are still recommended. They are listed as an option on my pre-operative paperwork:

You are required to take the following for the rest of your life:

  • Vitamin B12 (containing at least 2.5 mg or 2500 mcg per serving) weekly
  • 2 adult Multivitamins (or 4 children’s Multivitamins) daily
  • Iron fumerate or chelate
  • 2 Calcium Citrate (~500 mg Calcium per serving) daily

Doctors are still recommending Flintstones, but they are not an adequate source of nutrition for bariatric patients.

ASMBS Recommendations

The American Society of Metabolic and Bariatric Surgeons published nutritional guidelines for bariatric patients that specifically address multivitamin supplementation. According to the ASMBS, weight loss surgery patients should select “a high-potency vitamin containing 100% of daily value for at least 2/3 of nutrients.” Patients with a malabsorptive surgery, such as the Roux-en-Y gastric bypass or the duodenal switch, should take twice the adult dose to achieve 200% of the daily value for most nutrients. The ASMBS also recommends that patients “choose a complete formula with at least 18 mg iron, 400 mg folic acid, and containing selenium and zinc in each serving.” Their next recommendation is important:

Avoid children’s formulas that are incomplete.

So, how do we evaluate whether a children’s formula is incomplete? Well, the best way is to use the previous ASMBS guidelines. Let’s look at the nutrition information for Flintstones Complete and see if they meet the ASMBS guidelines.

As you can see, the list of nutrients actually contained in Flintstones Complete is relatively short. There are a few that are notably lacking, namely zinc and selenium. You’ll remember that the ASMBS says bariatric patients should be sure to choose a multivitamin that contains both zinc and selenium. Flintstones don’t. It’s as simple as that. Flintstones only contain four minerals: calcium, copper, iron, and phosphorus.

Vitamin Sources

If you’ve had Roux-en-Y gastric bypass, your anatomy has been altered. In addition to malabsorbing micronutrients, you have a decreased production of stomach acid. This changes how you break down and absorb vitamins and minerals, making the formulations of micronutrients vital.

This distinction is important in children’s vitamins, especially for vitamin A. Children’s vitamins rely on beta-carotene as a source for vitamin A. (The other form of vitamin A used in Flintstones is identified simply as “Vitamin A Acetate.”) For children, this is fine. Kids produce a lot of stomach acid. Their bodies can convert beta-carotene into a usable form of vitamin A. Unfortunately, as we age, our concentration of stomach acid decreases, and beta-carotene is not longer the best source of vitamin A. This is especially true for gastric bypass patients. Patients with achlorhydria cannot rely on beta-carotene as a source for vitamin A. As a result, the vitamin A in Flintstones is not accessible to gastric bypass patients. And, remember, vitamin A is a fat soluble vitamin; it is easy for weight loss surgery patients to become deficient in vitamin A as a result of malabsorption.

The iron in Flintstones is also a problem for patients with gastric bypass. While ferrous fumerate is an adequate iron supplement for normal-gutted individuals, it is problematic for gastric bypass patients. Once again, the lack of stomach acid plays an important role. Ferrous fumerate is a ferrous salt; ferrous salts requires a high concentration of stomach acid to be converted to the form of iron that can be used by the body. The ferrous salt simply will not dissolve in an achlorhydric environment, such as the digestive system of a gastric bypass patient. As a result, the iron will not be available to the body in a usable form. The Iron Disorders Institute puts it quite simply: an individual with an achlorhydric digestive system, such as an RNY gastric bypass patient, “will derive no benefit from the iron supplement” if it is a ferrous salt. Gastric bypass patients will not absorb the iron in Flintstones vitamins.

Gastric bypass patients also will reap no benefit from the calcium in Flintstones. Remember, we need calcium citrate.

The Cost Argument

Some doctors recommend Flintstones because they’re understood to be an affordable option. So, I went to to see how they measure up with the competition. Here’s what I found. The prices found through the links may vary, as prices change frequently on Amazon.

Flintstones Complete 200 tablets for $21.11$0.106 per tablet $0.42 per day(4 tablets)
Centrum (tablets) 365 tables for $26.98$0.0739 per tablet $0.148 per day(2 tablets)
100 tablets for $9.96$0.096 per tablet $0.199 per day(2 tablets)
Centrum Silver
120 tablets for $24.48$0.204 per tablet $0.408 per day(2 tablets)

Every other drugstore option works out to be cheaper than Flintstones. Cost is not an acceptable argument.


For review purposes, I actually purchased a bottle of Flintstones Complete. I chewed up Wilma, and I have to say, Flintstones are one of the least pleasant chewable vitamins that I’ve tried. They are very chalky and artificial tasting. I definitely would not recommend them based on taste.

The Bottom Line

When you have bariatric surgery, you permanently alter the way your body handles nutrition. It becomes your responsibility to provide adequate nutrition; Flintstones simply do not provide the nutrition bariatric patients need. It is irresponsible for physicians to recommend them, and it is unwise for patients to continue to take them once they know better.

Once you know better, do better.


American Society of Metabolic and Bariatric Surgeons. ASMBS Allied Health Nutritional Guidelines for the Surgical Weight Loss Patient. Surgery for Obesity and Related Diseases 2008; 4: S73-S108.

Iron Disorders Institute

Tang, G., Serfaty-Lacrosniere, C., Camilo, M.E., & Russell, R.M. Gastric acidity influences the blood response to a b-carotene dose in humans. American Journal of Clinical Nutrition 1996; 64: 622-626.

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5 Responses to “Guest Post: What’s the Fuss about Flintstones?”

  1. Karen Ogle says:

    Great post, Andrea and thank you for sending me her way. I’ve been through hell the last few weeks with malabsorbing most of my psych meds. It has been bad enough that you would think I was not even medicated. I will love being able to take that study to my surgeon next month. Hugs.

  2. Andrea says:

    Kaitlin has more of a mix of emotional posts of what it’s like to go through surgery from a newbie perspective (just out a year or so) as well as understanding the science-y stuff, so it’s a good mix.

  3. Jennifer says:

    I have been taking Flintstones, which ones do you personally take? Could you please email me your response? I might forget to come back here and check for an answer. Thank you!

  4. Andrea says:

    I will email as well, but to put this out there -

    I take Centrum as my multivite. I don’t do chewables, though. They DO make Centrum chewables, but if you are looking for something that is specifically formulated for our guts, I would have to say either Bariatric Advantage or Celebrate.

  5. Jeannette says:

    No offense, but the flinstone vitamins do contain zinc. 12mcg and 80% of an adult RDA.

    I dont support or take flinstone viatmins, but the article should be accurate if you are going to render an opinion.

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