Monthly Archives: April 2014

Can You Trust Your Supplements?

images35DGQ9E6If you are like more than 50% of Americans you took one or more dietary supplements today. The use of dietary supplements has been increasing over the past 20 years. What you once could only find in health food stores is now available in drug stores and grocery stores. It has even become common for conventionally trained medical doctors to recommend multivitamins, fish oil, probiotics and vitamin D. Most of the patients that I work with are taking multiple supplements before I start working with them.

While I recommend dietary supplements to many of my patients I do have concerns about the safety, interactions, and quality of dietary supplements. I will be addressing safety and interactions in future blogs, but in this blog I want to focus on quality issues with dietary supplements.

A recent quality evaluation by the company Consumer Labs found that 20% of the vitamin D products that they tested failed their quality testing. Two products contained almost twice as much vitamin D as was listed on the label, once product contained unacceptable levels of lead, and two products did not disintegrate within the expected 30 minutes. Trader Joe’s Calcium Citrate with Vitamin D contained 175% of the amount of vitamin D on the label and still had not disintegrated after an hour. So while you might save a little money on buying your calcium and vitamin D from Trader Joes, if it doesn’t break down in your digestive tract you might as well be throwing your money away.

In another evaluation they found that 16 of 42 multivitamins tested either had less of a nutrient or nutrients than the label stated, had more of a nutrient or nutrient than the label stated, or didn’t dissolve under normal circumstances. While the benefits of taking a multivitamin can be debated, if you are taking a multivitamin it would be good to know that it contains the amounts listed on the label and also that it is going to dissolve in your stomach as opposed to in the sewer.

Several years ago an analysis of Ayurvedic herbal products purchased from health food stores in the Boston area found that over 20% of them contained dangerous levels of lead, mercury, and arsenic. While the amounts in a single pill were not enough to cause a problem, if you were taking them every day for months, the toxic exposure could begin to have serious health consequences.

A study done at Bastyr University looking at the quality of probiotic supplements found that only one product out of twenty contained exactly what the label claimed it to contain.  30% of the products were contaminated with other organisms and 20% had no growth of any bacteria.

These examples unfortunately are just the tip of the iceberg. Other issues have included adulteration with anabolic steroids, high levels of toxic solvent residues, failure to contain the herb or probiotic species listed on the label, and inclusion of rancid oils.

While I have a great appreciation for dietary supplements, it has become clear to me that there is a great deal of variability in the quality of products sold as dietary supplements in the United States. While there has been an increased effort by the FDA to enforce basic quality standards, the supplement industry remains largely under regulated. The FDA does now require supplement companies to follow specific good manufacturing practices (GMP) in regards to the manufacturing of the product, but there is not the infrastructure to adequately enforce these and even if they did there is concern that the FDA standards may not be adequate enough to ensure that supplements are safe, free of contaminants and contain the substances that the label says that they do. The GMPs also don’t regulate the effectiveness of the product, the forms of the ingredients, where the herbs and nutraceuticals come from, or whether or not the additives or fillers used might have negative effects.

Fortunately there are some companies that have taken it upon themselves to make sure that they are producing high quality products. These companied not only follow the FDA regulations, they go beyond these standards to ensure that when you buy one of their products it contains the ingredients they say they do, in the amounts listed on the label and have been tested to make sure that they do not contain heavy metals, rancid oils, microbes, pesticide residues, solvents, or pharmaceutical drugs.

In order to find these companies, I have had any company that I recommend complete a detailed quality control survey so that I can tell if they meet the standards that I think are important to ensure that the supplements that I recommend to my patients are safe. In addition to the surveys I have sent out I have also had the students in the Supplementation and Whole Foods Nutrition course that I teach for the University of Western States send out the surveys as one of their assignments and so I have gotten to see a wide range of responses.

Based on those responses I have found several companies that I feel meet a high enough standard for me to recommend safely to my patients including: Thorne Research, Metagenics, Designs for Health, Integrative Therapeutics, Vital Nutrients, Biotics Research, Douglas Labs, and Pure Encapsulations.

Some of these companies can be found on the Order Supplements page of this website. In addition many of these can be purchased at Apothecary by Design in Portland and True North in Falmouth.

So the next time you are tempted to buy that cheap bottle of vitamins remember that you may be getting more (or far less) than you paid for! In my next blog I’ll take a look at some of the potentially dangerous interactions between dietary supplements and the medications that you may be taking.


Find the foods that are healthy for you.

4fFood sensitivities are a common occurrence affecting more than 35% of the population Food sensitivities can cause a wide range of symptoms including:

  • Weight gain
  • Heartburn
  • Constipation
  • Diarrhea
  • Low energy
  • Lack of focus
  • Irritability
  • Depression
  • Chronic congestion
  • Skin rashes
  • Poor sleep
  • Muscle aches
  • Joint pain


Unlike food allergies which cause immediate onset of symptoms, symptoms of food sensitivities can be delayed by hours or even days. The wide variety of symptoms and the delay in symptoms presentation can make it very hard to make a connection between the food and the reaction. Because of this, many people who suffer symptoms caused by food sensitivities don’t realize that a food is to blame.

Uncovering hidden food sensitivities can often be a difficult task. Lab tests used to test for food sensitivities can be costly and often unreliable. Elimination and challenge diets are the gold standard for diagnosing foods sensitivities, but they can often be hard to follow and if done incorrectly can be hard to interpret.

To help you to determine if any of your symptoms are being caused by adverse reactions to foods, I am offering a four week elimination diet class beginning on Tuesday April 29th. This class will help you to successfully undertake a comprehensive elimination diet, determine which foods are causing your symptoms, and learn how to potentially decrease your food reactions and prevent new ones from developing.

The four week group program cost $195 and includes:

  1. Elimination Diet Program Binder with the detailed, instructions, recipes, tips, resources and tracking tools needed to be successful with the program.
  2. Access to an Online Group for participants only, moderated by Dr. Knight.
  3. Four Group Sessions held on Tuesday evenings at my office at 222 Saint John Street in Portland from 6:30 to 8pm:
  • April 29th: Getting Started
  • May 6th: Strategies for Successful Elimination
  • May 13th: How to challenge.
  • May 20th: Discoveries and life beyond the program.

To register or for more information call (207) 805-1129 or email [email protected]