Wednesday, February 6, 2008

Rx Essentials: Are They Really?

You may have seen a product line on the shelves recently called RxEssentials. The marketing for these new vitamin supplements is actually pretty slick; Nature Made is a big company, and they do produce some quality products. A lot of their supplements are USP Verified, which means that the United States Pharmacopoeia has verified that what's on the label is what's in the bottle. Always a good thing. I have to commend them for going the extra mile to meet those standards.

RxEssentials, on the other hand, is a clever way to get you to pay more for your vitamins than you would otherwise.

The basic claim behind RxEssentials is that each formulation supplies key nutrients for people taking specific medications. Sometimes this is the case because the drug blocks or reduces nutrient absorption; in other cases, the manufacturers seem to be taking a page out of Pauling's orthomolecular medicine, which posits that nutritional deficiencies (or, for extra woo flavoring, "imbalances") are the root cause of basically every disease ever. There's a little bit of truth to some of this reasoning. Some drugs do reduce absorption of specific vitamins or minerals. Isoniazid, which is used to treat tuberculosis, can reduce vitamin B6 levels to the point where patients may actually suffer neurological problems if they fail to supplement. And methotrexate, an immune system modifying drug, is usually given with folic acid to prevent deficiency--methotrexate actually works by inhibiting the conversion of folic acid to its active form, tetrahydrofolate.

So let's look closely at RxEssentials. What do they offer that your basic multivitamin might not? They cost, on average, about $10 a bottle for 60 tablets, a two-month supply.

The arthritis formula is recommended for anyone taking ibuprofen, naproxen, or aspirin to relieve arthritis pain. It contains vitamin C, vitamin D, and folic acid. Fail. None of these drugs are going to significantly impair absorption of these nutrients, and most of that 500 mg of vitamin C is going to end up excreted in the urine. Vitamin C is abundant in the diet, and vitamin C tablets are dirt cheap ($6 for 250 tablets is pretty common). The most valuable component of the formula might be the vitamin D; most people with arthritis are older, and most older people get insufficient vitamin D. But vitamin D isn't expensive, either. An inexpensive multivitamin a day is going to cover everything.

The cholesterol formula is designed for patients on statin drugs--Lipitor, Zocor, or their close cousins. As expected, it contains CoQ10. Oh, and B-vitamins, but those are in everything, including bread. CoQ10, or coenzyme Q10, is commenly touted as a means of preventing muscle damage due to statin use. Unfortunately, the evidence doesn't hold up. Some studies show benefit; others don't. One study using 200 mg of CoQ10 daily showed no benefit but noted that patients might respond due to the placebo effect. Another showed some benefit with a 100 mg dose. The evidence is inconclusive. CoQ10 is also kind of expensive, as much as $20 for a bottle of 30 softgels containing 100 mg each. RxEssentials might actually be the better buy if you're dying to try CoQ10, but that's not saying much.

I have to admit that I find the depression formula particularly lacking. B-vitamins, folic acid (maybe for pregnant, depressed women?) and vitamin D. Yes, it's the old "depression is caused by vitamin deficiencies" gambit, except that they're telling you to stay on your Zoloft or Prozac and "supplement." More orthomolecular medicine at work. B-vitamins are important cofactors in energy production; the idea is that a lack of B-vitamins results in "decreased energy," which somehow translates into "depressed mood," "sleep disturbances," "loss of pleasure in daily activities," and, my personal favorite, "suicidal ideations." There is no evidence whatsoever that nutrient deficiency is a primary cause of depression; B-vitamin deficiencies can cause neurological problems, but B-vitamins are so prevalent in the diet that hardly anyone has a problem meeting their needs. You're going to get all this stuff in your (much cheaper) multivitamin. Vitamin D is great for bone health, but store brands are generally cheaper. The manufacturers are clearly assuming depressed people don't get enough sun.

I was really hoping that they'd get their heartburn formula right. An acidic environment is important for the absorption of iron, and chronic acid-suppression therapy coupled with low iron intake creates a situation where deficiency is a very real possibility. Except that there's no iron in the supplement! None! Instead, they're pushing B-vitamins again. B-vitamins are a very necessary component of nutrition. They aren't worth paying a lot of money for; they're in everything, including enriched flour, grains, vegetables, bananas, and even beer (although alcoholic beverages are not a good source of nutrients and chronic alcohol consumption, in excess, can cause other problems). Oh, and they throw in some calcium, but only 120 mg per dose. For reference, most people need 1200 to 1500 mg of calcium per day in divided doses (you can only absorb 500 mg "at a time"). It would've been easy to formulate an iron-replacement regimen for patients with acid reflux; I can't believe they blew this one.

Finally, we have the diabetes formula. In case you hadn't guessed by now, their supplement for diabetics includes--yeah, it really should've been obvious--B-vitamins! Oh, and folic acid. We wouldn't want anyone giving birth to babies with neural tube defects. Except that, of course, that's not why the manufacturers chose to include folic acid in the supplement; it's to "maintain energy." Argh! Yes, patients with diabetes have problems with "energy" metabolism; they can't properly utilize glucose to fuel cells because they produce insufficient insulin. But taking extra B-vitamins doesn't help the body utilize glucose any better, unlike oral diabetes medications or insulin injections.

To summarize, RxEssentials gets the big thumbs-down. The manufacturers claim that RxEssentials "provide specially selected nutrients." But as you can see, most of the products contain the same ingredients: B-vitamins and folic acid. At least they're being responsible and telling people that RxEssentials are not a replacement for their prescription drugs.

There are therapeutic precedents for taking specific nutrient supplements for various conditions or with particular medications. I already mentioned a few. But any responsible physician is going to prescribe those nutrients alongside the medication--especially if serious harm will result from not having them. Note that none of these products are for people on methotrexate! Arbitrarily deciding you need to supplement is a waste of time and money.

So what should you do if you think you have a nutritional deficiency? Talk to your doctor. Evaluate your diet with information from appropriate food guides. Nutritional deficiencies have a set of clear diagnostic criteria; less-specific concerns like "I feel tired sometimes" or "I get a lot of colds" are generally not indicative of a problem. Everyone feels tired sometimes. B-vitamins are not effective in reducing the effects of "stress" or a replacement for a good night's sleep. You probably don't need RxEssentials. And even if you did, a cheaper multivitamin would offer the same benefits.

Like most dietary supplements, RxEssentials relies on good marketing to make sales. It's too bad that marketing is all they have.

1 comment:

bj said...

I think it is important to be critical to the products described. However, I would like to make some comments to your text. You mention orthomolecular medicine. If you are interested in learning more about this, you will soon learn about biochemical individuality, a concept saying that we are all different in our biochemistry. If you want to find good treatment, the biochemistry of the person may be even more important than the diagnosis which in current mainstream medicine often is mainly based on symptoms. Biochemical individuality means that our needs for different nutrients vary and in the evaluation of the individual person, the RDA is of very little help. Actually, there is a lot of scientific support that specific nutrients can make a difference in treatment and prevention of disease. However, a lot of this can be difficult to find and you need to have a critical attitude towards all claims in any direction. To really get a primary knowledge you need to test foods and nutrients in sound ways. If you only read and listen to the current authorities in a field you will often get lost in prejudices and unfounded statements. If you are interested in the science in this field there are a lot of books and papers. A paper describing the importance of gene polymorphisms for the great variation in different nutrients for different people is:
Ames B et al. High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased Km): relevance to genetic disease and polymorphisms. Am J Clin Nutr 2002:75:616-58.