In this supporting document we’re going to be discussing dietary supplements. In Canada supplements are part of a category of products called natural health products.
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Source: http://www.hc-sc.gc.ca/dhp-mps/prodpharma/applic-demande/guide-ld/scha_guide_ld-eng.php
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Shown here is Health Canada’s definition of a natural health product. As you can see here, it is anything that comes from a plant, a microorganism, or a nonhuman animal. It’s also an extract or isolate that comes from plants, microorganisms, or nonhuman animals. It includes a long list of vitamins, amino acids, fatty acids, minerals or a probiotic, which is a microorganism. It also encompasses synthetic duplicates of any of the substance listed in items 2 through 5. This is very important because it is often easier to synthesize a compound rather than extract it from living material, especially if it comes from a rare or expensive plant or animal.
So natural health products include vitamins and minerals, amino acids, essential fatty acids, which will be our primary interest in this nutrition course. Also included are herbal remedies, traditional medicines, and homeopathic medicines which we will not discuss.
Natural health products tend to occupy a space somewhere between food and drugs, as highlighted in yellow. Unlike food, which we consume for nutrition and energy, natural health products tend to be associated with some sort of therapeutic purpose. This could be related to the treatment or prevention of a disease, disorder, or abnormal physical state and to generally restore or correct functions of the body. They’re different from drugs in that they tend to be self-selected by the consumer and, so, unlike drugs, they must have a very much lower risk of harm.
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The regulation of natural health products is the responsibility of an office, within Health Canada, called the Natural and Non- Prescription Health Products Directorate. Shown here a quotation from the directorate that describes its function: which is to ensure that Canadians have access to natural health products that are safe and effective, while respecting freedom of choice and philosophical and cultural diversity.
The quote on the previous page discusses respect for freedom of choice and philosophical and cultural diversity. It means that natural health products include products that have traditional uses, provided they are not harmful. But it is important to realize that a natural health product, marketed on the basis of its traditional use, may not have a lot of scientific evidence to support its effectiveness. If a product does not have a traditional use, than scientific evidence to support its safety and effectiveness is required. One of the controversial aspects of natural health products is that many feel that the standard of evidence for effectiveness is very low – traditional use- or the availability of one or two studies, demonstrating effectiveness, is often sufficient to get government approval for many products.
To ensure the safety of natural health products, manufacturers must demonstrate that they use what are called good manufacturing practices in the making of the product. And when this is demonstrated health Canada issues a license for the site of manufacture. This usually involves in an inspection of the premises and there are international agreements and arrangements, so that these premises can be inspected, even if they are not in Canada.
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Good manufacturing practices means that the product is what it says it is and this is not always as straightforward as it sounds. When dealing with plant material it can sometimes be a challenge to properly identify a plant and so sometimes mistakes are made. There was a study some years ago where researchers used DNA analysis to identify plant material and they found that many natural health products, even those produced by reputable manufacturers, did not contain the stated ingredient. Safety also means a product is not contaminated by microbial or chemical contamination; e.g. heavy metals such as lead or mercury and do not contain prescription drugs. The addition of prescription drugs to natural health products is one of the most common ways that unscrupulous manufacturers can improve the apparent effectiveness and, hence, the sales of their products, but it is both illegal and dangerous. Fortunately this happens rarely in Canada, although occasionally Health Canada will announce the recall and seizure of products found to contain drugs.
The second item that manufactures must demonstrate is that the product is effective for its stated purpose. As we have already noted this can be through documenting traditional use or by providing scientific evidence. There is also a third easier way and for most nutritional supplements this is the approval pathway taken. It is to cite a document written by Health Canada called the Natural Health Product Ingredient Database Listing of Monographs. A monograph provides scientific information on the acceptable doses and uses of a product.
Manufacturers can market any natural health product in the Natural Health Product Ingredient Database Listing of Monographs provided they agree to follow the guidelines of the monograph. Doing this can result in rapid approval for the product. For example, vitamin C has a monograph. If a manufacturer wants to market vitamin C supplements, and agrees to follow the guidelines of the monograph on Vitamin C, this product can be approved within a few weeks. If, on the other hand, the manufacturer has a product that is not listed in the database, or wants to market it for a purpose that is not listed in its monograph, then stronger scientific evidence is required, such as a review of the scientific literature. In some cases the manufacturer may be required to conduct their own RCT.
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This is a screen capture shot of the Health Canada website that emphasizes that the monographs represent pre-cleared information, as highlighted in yellow. Because it is pre-cleared, manufacturers use it to speed the approval of their products. Monographs are also reliable sources of product information for consumers.
http://webprod.hc-sc.gc.ca/nhpid-bdipsn/monosReq.do?lang=eng&monotype=single
Here is a screen capture shot of the table of contents (partial) for the listing of monographs and you can probably recognize the names of some popular natural health products.
This is the monograph for vitamin D and this would be what a manufacturer, who wants to market vitamin D supplements, would look at. So we can see here that we have listed the names ❶, the source material for the supplements ❷, and the type of dosage ❸, which in this case is orally administered and can take several forms. Natural health products are limited to products taken orally or administered topically on the skin.
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Described here are the uses for which the vitamin D is approved. You can see they include uses such as a factor in the maintenance of good health, helps in the development and maintenance of bones development and maintenance of teeth, helps the absorption and use of calcium and phosphorus and also that calcium intake
when combined with sufficient vitamin D and a healthy diet and regular exercise can reduce the risk of developing osteoporosis. If manufacturers are happy to list these uses, when labeling their supplements, then they need only confirm with Health Canada that they are following the monograph, to get rapid approval for their
product. If, however, a manufacturer wants to state, on the label, uses that go beyond those listed here, then additional scientific evidence has to be submitted.
In addition to listing the uses, the monograph also provides information on the acceptable range of doses and indicates whether any particular warnings about the safety of the product or adverse reactions to the product are required. As you can see here for vitamin D no risk information is required, on the supplement label.
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Ch 9: pg 435 3e
Here is part of the monograph for vitamin E. For this vitamin, unlike vitamin D, there are a significant number of cautions and warnings that need to be placed on the label, that depend on the dose of the vitamin. For doses greater than 180 mg per day, you should consult a health care practitioner if you have cancer. This is because of some studies that have shown that vitamin E may interfere with cancer treatment. Cancer treatments, like radiation, act by generating free radicals, chemicals that interact with biological materials and damage them. So free radicals can be effective in killing cancer cells. Vitamin E is an antioxidant that can neutralize the impact of free radicals. In a healthy cell, this is a good thing because it protects the cell from damage or death. But if you’re dealing with cancer cells, you do not want to protect them from damage or death. There’s also a warning to consult your doctor if you have cardiovascular disease or diabetes, again because there have been some studies that suggest that high doses of vitamin E may increase the risk of these diseases. Finally vitamin E acts on the body as an anticoagulant, meaning that it prevents the clotting of blood, an action that is often referred to as blood thinning. People who have had cardiovascular disease often take medication that also has blood thinning action, so the combination of vitamin E and these drugs could increase the risk for hemorrhaging or bleeding; so this caution is provided as well. It’s important to recognize that even an essential nutrient like vitamin E can be harmful at some doses and for some individuals.
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Natural health products are labeled like drugs. Shown here are the components that should appear on the label, including the product name, the product license holder, which is the manufacturer of the supplement, and a natural products number or NPN. This number is very important. If there is no NPN, then the product has not been authorized for sale in Canada. You will find such products on the shelves in health food stores and even in some drugstores. Many products that do not have NPNs are imported from the US, and are probably safe, but it is best to use supplements with an NPN.
In addition to the NPN, the product’s medicinal ingredients and non-medicinal ingredients will be listed, as well as information about dosage, its recommended use, and any risk information. For many products, this will exactly duplicate the information in the monograph.
The labeling of natural health products differs substantially from food. Food has a nutrition facts table, which indicates percent daily values, and will have an ingredients list. A natural health product, such as a vitamin-mineral supplement, on the other hand, must list the nutrient content as a weight in grams, milligrams, or micrograms. There’s no information on the kcalorie content of the supplement. Instead there is a list of medicinal and non- medicinal ingredients. If you see a nutrition supplement labeled with percent daily values, it is probably a supplement that comes from the United States, because percent daily values are listed there.
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For additional listings
There are a great many types of supplements that are available and many of them are described in the textbook. If you are interested in some of these, you can read about them, for your own interest.
There is one category of supplements that I do want to talk about: weight loss supplements. The compounds that have been used in these supplements over the years have fallen into two categories: the ones that are effective, but have potentially dangerous side effects and are now banned. And compounds that are safe but have only a modest effect.
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This table, which you don’t have to memorize, list some of the compounds commonly found in supplements approved for use in Canada as aids in the management of weight. They are safe when used as directed; but research shows that they have at best a very small effect on weight loss.
This required textbook reading describes some of the dangerous weight loss compounds that are no longer permitted for use, as well as some of the safer supplements available. Please be sure that you can answer the questions listed here in order to be prepared for your term test.
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This concludes the discussion of natural health products, but before you go, try the self-assessment questions below.
Self-Assessment Questions
1) According to Health Canada, which of the following is a natural health product?
a) Over-the counter drug
b) Injectable form of insulin
c) Iron supplements that treat anemia
d) Injectable form of vitamin B12
2) The following statement was found in the Listing of Monographs under vitamin C: “Helps in the development and maintenance of gums.” What is being described?
b) Use or purpose
c) Disease risk reduction claim
d) Dosage form
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3) Sara goes into a health food store and finds a vitamin supplement without an NPN on its label. What does this mean?
a) The product has not been authorized by Health Canada
b) The product is harmless and does not require an NPN
c) The NPN is not found on a supplement label, but can be looked up online.
d) Vitamins supplements do not require NPNs.
4) Which of the following is NOT mandatory on a natural health products label?
b) Risk information, if applicable
c) Directions for use, including dosage
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