I’m thinking about pregnancy, so my nutritionist suggested I start on prenatal vitamins. Well, that part I’m not skeptical about. But then she went on to say I should buy powdered vitamins that you mix with water, because then that mixture is “isotonic with your body’s internal pressure” and so “you absorb 100% of the nutrients.” This set off my Bullshitometer, big time. But I wanted to make sure, since prenatal nutrition is a big deal for any responsible wannabe mom. Thanks!
Nutritionist: Although technically a person with a master’s degree in nutrition can be called a nutritionist the mass majority of people who call themselves a nutritionist do not have a degree and many states do not require a degree or certification of any kind to use this title.
Dietitian: Requires a degree. A registered dietitian must be credentialed by the American Dietetic Association and to get this credential one needs at least a four-year Bachelor’s degree in nutrition and dietetics (or graduate degree), and must complete an internship and pass a national registration exam from the American Dietetic Association.
Take that as you will. A retired athlete or a part time chef could get a certificate that says they are a nutritionist. I could go to “Hollywood Upstairs Herbal School” and get a certificate from Mack the yoga guy that says I am a nutritionist. This is not to insinuate that all nutritionists are uneducated or uniformed, many are indeed quite credible. This is just a warning that a healthy dose of skepticism is good when that title is tossed around.
Now that we have that out of the way, here is a message about prenatal vitamins in general:
Prescription prenatal vitamins here in the USA are regulated by the FDA and have to have what they say they have on the label. They also have to do what they say they will do. Over the counter supplements are not regulated. Vitamins handed or recommended to you by a nutritionist who claim they are “isotonic with your body’s internal pressure” and “you absorb 100% of the nutrients” is code for: I do not have a degree in biology, medicine or pharmacology and I know less about these topics than that wacky Skepchick-artist they call Surly Amy.
Now on to the term isotonic.
I’m not a dietitian, doctor, biologist or a pharmacist so I contacted my super-smart twitter friend, PharmacistScott, aka: Scott Gavura to get the lowdown on what isotonic actually means.
This was Scott’s response to my inquiry:
Tonicity refers to the number of dissolved elements or molecules in a solution. For safety and comfort, many liquid drug products must be “isotonic” with our bodies when administered. Isotonicity means that both the solution and our body fluid has a similar amount of dissolved particles in them. Injectables, eye drops, and nasal sprays are all products that would be very irritating on our tissues if they were not isotonic.
Drug products and supplements we take orally, however, do not need to be isotonic. That’s because anything we consume is deposited into a bath of stomach acids and digestive juices, immediately changing the initial tonicity. So an “isotonic” vitamin won’t be absorbed any better than any other vitamin – liquid, tablet or capsule. What’s further there’s no evidence to suggest that liquid vitamins in general are superior to tablets, though they may be preferable (and worth the extra cost) to people who want a vitamin supplement but don’t like tablets or capsules.
Here’s a definition of tonicity. Bottom line is whatever you eat is mixed in with your stomach acid. It doesn’t matter if it’s in a liquid state when you consume it. It must dissolve to be absorbed. And there is no evidence that an “isotonic” vitamin product is superior.
Another issue that you should be aware of is that isotonic is a term that seems to be being pushed by a multi level marketing company. I am not going to link to them because they do not deserve the traffic. But the lack of evidence for the product combined with plenty of evidence for the traditional vitamin tablets would encourage me to get and to recommend regular prenatal vitamins prescribed or recommended by an MD.
Good luck with your planned pregnancy. I hope this helped!
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