Monday, February 1, 2010

Vitamins - Scientific Breakthrough or Marketing Hype? The Truth.

Some patients love their vitamins spending hundreds to thousands of dollars annually. At times, they will even forgo proven medical therapy. As more Americans go without health insurance coverage while others face higher office visits and copays, increasing number of patients are seeking alternative natural therapies instead of medical care. Are vitamins really the scientific breakthrough and secret that doctors refuse to recommend or are they simply marketing hype? As any medical school student will tell you, the correct answer to any question is: it depends.

For certain groups, pregnant women, patients with macular degeneration, and vegetarians, vitamins and minerals may be recommended as research finds them helpful. Prenatal vitamins have more folic acid which has been found to decrease the risk of neural tube defects in the fetus. Vegetarians may need to supplement their diet with vitamin B12, iron, and vitamin D, which are absent in their food choices.

Patients with history of gastric bypass should be on a multivitamin that contains iron and vitamin B12. The surgery, which is used to cause weight loss in morbidly obese patients, can bypass part of the digestive tract responsible for absorbing these nutrients.

Women of all ages should take calcium and vitamin D to improve bone density to decrease their future risk of osteoporosis. This means at least 1000 mg of Calcium daily and Vitamin D 800 to 1000 international units (IU) per day. Women over 50 should be taking 1500 mg of calcium day. A common misconception is that a multivitamin has enough calcium. It doesn't!A typical multivitamin has about 45 mg of calcium (a glass of milk is about 300 mg).

Aside from these individuals, the result of us with a balanced diet should get the right amount of vitamins and minerals. You don't need the large mega-dose vitamin packs found at your local warehouse store or nutritional shop. Not only are they expensive but also unproven.

If you still feel like you can't get through life without taking vitamins, then at least be aware of the following:

Limit the amount of fat soluable vitamins that you ingest, specifically vitamins A, D, E, and K. Unlike water soluable vitamins which excess amounts are excreted by the kidneys, fat soluable vitamins can build up levels in the body.

Vitamin A - toxic levels begin at ingesting more than 50,000 IU daily. Upper limit of tolerable intake (what is considered the upper limit of normal but still safe) is 10,000 IU. Recommended daily allowance is 3,000 IU.

Vitamin D - upper limit is 2,000 IU. The current daily allowance is 600 IU. A new recommendation is expected in May 2010 by the Food and Nutrition Board. Vitamin D is obtained by the skin via sunlight exposure. With people indoors more often than generations ago and possibly the increased use of sunscreen, doctors are seeing more cases of vitamin D deficiency. Your doctor may prescribe a weekly dosage of 50,000 IU weekly for 3 months to replace. Low levels of vitamin D can cause muscle pains, so if a constant problem, ask your doctor to check your levels. (Cod liver oil, incidentally, is rich in vitamin D and is probably why growing up in Canada I had a lot of it during the winter. Ick.)

Vitamin E - recommended dosage is 22.4 IU with the upper limit of tolerable intake no more than 1500 IU. Some research suggested that there was increased mortality for those individuals taking more than 400 IU per day. Because of its antioxidant properties, researchers thought taking more was better. It wasn't.

Vitamin K - found in green leafy vegetables, it is the only fat soluable vitamin where there is no defined upper limit for toxicity. Overdose of vitamin K is rare.

Am I against vitamins? Of course not. For some patients in fact they are recommended. What I am against is, however, having individuals spend their hard earned money for therapies that aren't proven. Note that the FDA, under current legislation since 1994, has no oversight over nutritional supplements.

This is why all vitamin package inserts have the following statement:

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Want to live well? A better insurance policy than vitamins is to not smoke, perform regular physical activity, take in five servings of fruits and vegetables, and possibly drinking alcohol in moderation (as a doctor I can't recommend that, but if you drink already, it might be o). Researchers found individuals who did all four behaviors added 14 years to their lives. Why don't more of us these activities? They all take some effort. Swallowing vitamins are quicker and easier.

If I still haven't convinced you not to take unnecessary vitamins, then at least check with your doctor before stopping your medical therapies or adding supplements that can interfere with your treatment.

Finally, please avoid colon or total body cleanses. Sounds natural and healthy, but again aren't required. A product found at a large nutritional chain's special "anti-oxidant" formulation basically consists of fruits, vegetables, and fiber. You can do that yourself for a lot less and it probably tastes better too.


The Liz Army said...

Dr. Liu:

What do you think of glucosamine?

My knees make a crunching sound and have become achy and painful over the past few years. I started taking glucosamine a while back and though the crunch sound persisted, the pain went away.

When I learned about my cancer (and epilepsy) I chose to stop using the glucosamine for fear that it would interrupt other treatment.

Within a few months my achy joints came back. I emailed my oncologist and he said it would be OK for me to use glucosamine again--but with chondroitin. Since adding that back to my daily regimen my knees are feeling fine again.

What's the deal with chondroitin? Why would my doctor suggest that over glucosamine alone?


-- Liz

Davis Liu, MD said...

Not sure. Some thought was the combination would be better than the glucosamine alone. Chondroitin has consists of components that make up the cartilage. Glucosamine is thought to slow down the degeneration of cartilage.

The good news is neither supplement has side effects and it sounds like they don't interfere with your medications or treatments.

My patients do find taking either one helpful for joint pains.

Hope that helps.

Anonymous said...

very thoughtful post. the topic of supplements is very controversial even among naturopathic physicians.
here are my thoughts:To take or not to take supplements.
read it here:

Mary said...


This is the assistant editor for which is a medical publication offering hospital news, information and reviews. We also cover a wide variety of medical topics, some of these articles being relevant to Health Care reform as you will see from the homepage of our site. We are in the process of updating our health care news section with dozens of articles on the reform and other relevant issues. If possible I would like to be included within your blog roll, offering our information as a resource to your readers and essentially building a relationship between our sites. Please let me know if this addition can be made, Thanks!

Please email me back with your URL in subject line to take a step ahead and to avoid spam.

Thank you
Mary Miller,

Leigh Ann Otte--TheDoctorWriter said...

Thanks for sharing such an evidence-based conclusion. Like you said, it's more than a health issue; it's a money one these days!

shilpa said...

The good news is neither supplement has side effects and it sounds like they don't interfere with your medications or treatments. This sounds fantastic ! I honestly can’t wait I hope there isnt too much wait for it to be shown in the UK but the second it does you can count on me watching it.



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