Let's continue this discussion by considering Walter Willett's recommendation that we take a low potency multivitamin and mineral supplement. I qualify that recommendation to mean a good quality low potency multivitamin. The first thing we need to realize is that pretty much the only thing that changes in potency between low, medium and high potency multivitamins is the amount of the B complex vitamins. These are among the most widely supplemented vitamins. They are often marketed as "stress" vitamins because our requirements for B vitamins increases when we are under greater stress – and people today experience a lot of stress! B vitamins are not easy to obtain in high doses from foods. There are a few foods, like liver and certain kinds of yeast, that are relatively high, but eating large quantities of these foods is not necessarily ideal. Firstly, the liver is an organ of detoxification and one of the most toxic organs in the body. Eating the liver of various mammals and fish was a good source of many important nutrients in the past, but these days I don't recommend eating liver or other organ meats on a regular basis or even at all due to their toxicity. Eating brewer's yeast or other kinds of nutritional yeast is also not necessarily the best solution. They need to be eaten in fairly large amounts to provide similar doses of nutrients to those found in supplements and are not a normal component of the human diet in these quantities. Also, many people have sensitivities to yeasts, and they don't necessarily provide B vitamins in the correct ratios that match our daily requirements. I'm not saying that we should never eat these foods, only that it probably isn't ideal to eat them in large quantities or too regularly. Also, if we do eat liver, we should only eat liver from healthy, organically raised livestock. Liver from wild animals is less desirable. Even in the remotest regions it has been known to contain significant quantities of mercury, PCBs and other toxins that come from the activities of the logging and mining industries or arrive in the air, rain and snow. Also, wild game tends to be contaminated with lead if it is killed using bullets that contain lead. Although traditional peoples used as much of an animal as possible to honour the spirit of the animal and because it makes practical sense, unfortunately it is no longer a good idea to eat the organs of wild game on a regular basis.
The flesh of wild game such as white-tailed deer (Odocoileus virginianus) can contain significant toxicity, even in remote areas.
Because consuming B vitamins in larger doses helps people to better deal with the affects of stress, B complex vitamins are very often supplemented, usually in medium to high potencies. This is not something that I recommend, and if we want to approach this from a "holistic" perspective, it is not very holistic. Most B vitamin supplements have the same dose of every B vitamin, usually 25, 50, 75 or 100 mg (mcg for a couple of them). However, our body doesn't use them all in the same amounts and these dosages are grossly in excess of what we need. A good quality B complex will have a range of doses of the individual B vitamins corresponding roughly to the relative amounts that we require. Ideally the dosage range should be between 5-10 mg (or mcg) for the lower dose B vitamins, and 15-25 mg (or mcg) for those required at a higher dose. It depends on the individual vitamin. Even at this dose, no matter how stressed out we are, our urine will still turn bright yellow after we take them. This means that the dose has exceeded our requirements and the excess is being flushed out by our kidneys. Technically, it is only riboflavin that produces this colour in our urine, but if the dose of riboflavin that we are taking is excessive enough to change the colour of our urine, we can be pretty certain that the dose of the others is similarly excessive. We don't want to exceed our requirements by too much because it puts stress on our kidneys to have to filter them out of our blood in large quantities on a daily basis.
Secondly, in order to be efficiently utilized, B vitamins need to be taken together with other nutrients, particularly vitamin C and some of the essential minerals. This is why it is much more "holistic" to take B vitamins in the context of a multivitamin and mineral supplement rather than on their own. In addition, there are probably other nutrient and nutrient-like substances in food that interact with B vitamins and all of the other nutrients in a multivitamin in ways that we haven't even begun to understand. For this reason vitamin supplements should always be taken with a meal so that they are taken together with their natural counterparts and all of the co-factors that work together with them. In particular, fat soluble vitamins like vitamins A, D and E can not be efficiently absorbed unless they are taken with a meal that contains some lipid (oil or fat).
The other rationale for taking a multivitamin and mineral supplement is that some of the most common nutrients that are deficient in our diet are trace minerals. This is because trace minerals are not replenished by the synthetic fertilizers used in commercial farming. Also, the soils of some regions are naturally deficient in certain trace minerals because they don't occur in the bedrock that underlies the soil, which is where most of the minerals in soil come from.
A multivitamin is not a replacement for a good diet. It is a supplement to a good diet. A good diet is essential. However, people in our society tend to experience chronic stress of a moderate to high intensity. This can significantly increase our nutrient requirements. A good quality, low potency multivitamin and mineral supplement is recommended to make sure that we are getting all of the nutrients that we need in sufficient, or preferably optimum amounts on a daily basis.
In addition to a relatively low dose of B vitamins that are in ratios that approximate our daily requirements, a good multivitamin and mineral supplement should also contain the major trace minerals such as zinc, manganese, selenium, copper and molybdenum. The minerals should be in a form that is easily absorbed such as amino acid chelates, citrates and malates. Some forms such as carbonates and gluconates are not as well absorbed. Oxides are particularly not recommended because they promote tissue oxidation. Also, it is preferable to use a multivitamin that does not contain iron. This is because iron is a very powerful oxidizing agent and too much iron in our blood and tissues promotes oxidation and contributes to many chronic health problems. Most people in our society get too much iron because they eat too much meat. Many kinds of meat are very high in iron and it is in a form that is more absorbable than the iron in plant foods and water. Another issue with iron is that the forms of iron found in supplements are usually difficult to absorb. So, the iron in multivitamins isn't the best form to take. As a rule, I recommend iron-free multivitamins and, if there is reason to believe that someone needs an iron supplement, I give it to them separately in a highly absorbable form taken together with vitamin C, which also increases the absorption of iron. Fortunately, most companies offer iron-free alternatives these days.
The last point I would like to make about multivitamins is that many of the companies who like to market themselves as "higher quality" add herbs to their vitamins. This has become a common practice these days and it is bad news for consumers. It is getting very difficult to find decent multivitamins that don't contain herbs. Here I am not referring to concentrated plant-based antioxidant extracts like flavonoids, anthocyanins and carotenoids. These are excellent ingredients to include in a multivitamin and highly recommended. What I am referring to is the addition of popular medicinal herbs like ginseng, Ginkgo and Echinacea to vitamins. For the most part this is a gimmick. Usually the herbs are in forms and quantities that will not provide any medicinal benefit. They are included because they are popular. It is a selling feature that can increase sales and help justify charging higher prices for these products. Sometimes they are included in general multivitamins because the public (with the manufacturers help) will perceive some value to including them. In other cases they are used to give a product a more specialized function, like including traditional female reproductive herbs in multivitamins "for women". Unfortunately, most supplement manufacturers don't consult with experienced herbalists when developing their formulations. So, regardless of their intentions, they often end up including herbs in ways that are inappropriate.
Medicinal herbs such as common purple coneflower (Echinacea purpurea)should not be ingredients in vitamin supplements.
Although foods – especially plant foods – are medicinal to some degree, we have always made a distinction between plants that we eat and those that we reserve for specialized use when we need a more powerful medicinal action than what can be obtained from foods. Even though the herbs in these products are usually in quantities that will not provide any medicinal benefits, ingesting them in these small quantities can still cause our body, or microorganisms living in our body, to adapt to them so that when we really need their medicinal benefits they won't work as well even in the appropriate forms and doses. Medicines should never be abused. They can lose their effectiveness and in some instances they may even be harmful.
I have occasionally come across multivitamins that do contain concentrated extracts of herbs in therapeutic doses. This is still not desirable. Herbs are not meant to be used this way. We use them only when we need them and in the appropriate way. The moral of the story is that any vitamins that we purchase for use on a regular basis should not contain medicinal herbs.
Another issue concerning the use of vitamin supplements is that some vitamins in these supplements are in slightly different forms than those found in foods. In fact, the whole notion of "natural" vitamins is also for the most part an advertising gimmick. The only really natural vitamins are those in whole foods together with all of the other nutrients and co-factors with which they naturally occur. When you buy a "natural" vitamin, if it is a relatively good product the word "natural" really means "relatively complete, in more-or-less natural relative proportions with plant-based co-factors, a few ingredients from natural sources, mostly synthetic". There is a lot of misinformation out there about natural vitamins and manufacturers often go out of their way to promote it. For example, there are many products on the market called "Rosehips Vitamin C 500 mg". Most relatively educated consumers of natural foods have probably read that rosehips are very high in vitamin C. When they see a product called "Rosehips Vitamin C 500 mg" they tend to think that either each capsule contains enough rosehip powder to provide 500 mg of vitamin C or it contains 500 mg of vitamin C that was extracted from rosehips. What it really means is that it contains 500 mg of synthetic vitamin C with some amount of rosehip powder. It could be a very small amount, in which case the ingredient list will say something like "in a base containing rosehips". If it is a more substantial amount, it will specify some quantity, usually 50 or 100 mg. This is very different from how most consumers perceive the product. Although rosehips are a very rich source of vitamin C or ascorbic acid, they still only contain 0.03-1.3%, depending on the source. Therefore the amount of rosehip powder necessary to provide 500 mg of vitamin C is between 38 g (1.3 oz) and 1.67 kg (3.7 lb)! Even at the higher concentration it just wouldn't be possible for someone to eat that every day. It probably wouldn't be good for them either as rosehips have lots of other properties that are potentially problematic at this dose. Extracting vitamin C from rosehips is not practical either. Not only would it be prohibitively expensive, it would be extremely unsound from an ecological point of view to have to use that much rosehip powder to make every capsule of vitamin C. As it turns out, the ascorbic acid molecule is closely related to monosaccharides and can be manufactured very cheaply from glucose. The molecular form of synthetic ascorbic acid is identical to the natural form.
Sweetbriar rose (Rosa eglanteria) is a common wild source of rosehips.
In the case of other vitamins, there are a couple for which the synthetic version is slightly different than the natural form. This usually means that the synthetic form partially or completely consists of isomers of the natural form. These are molecules that have the same chemical formula but are a different shape. In these cases our body, usually our liver, can sometimes convert the alternative isomers to the natural form so they can be used by our cells. In some instances they may need to be converted in our intestines before we can absorb them. These processes are not 100% efficient. That means that for a few vitamins the absorption and utilization of synthetic forms might not be as efficient as their natural counterparts. However, because the amounts found in supplements are significantly greater than those found in foods, even allowing for poorer utilization of some of them, they are still going to contribute significantly to our daily intake. Fortunately, the main vitamin for which this is a concern is vitamin E and most better quality vitamins contain the natural form, d-alpha-tocopherol or d-alpha-tocopherol succinate, rather than the synthetic form, dl-alpha-tocopherol. You will note that I said that some synthetic vitamins "might not" be as efficiently utilized. This is because natural nutrients are not always absorbed efficiently from our food either. In addition, due to common dietary and lifestyle habits, most people in our society suffer from some degree of digestive deficiency. For many of them it is actually easier to absorb and utilize vitamins from supplements than from food. The exception is timed release vitamins. These are intentionally made more difficult to digest so that water soluble vitamins will be absorbed more slowly, otherwise they tend to be flushed out of our body by our kidneys pretty rapidly. Timed release vitamins are not recommended because they are not always digested efficiently. It is better to take smaller amounts of vitamins more often than to take larger amounts in a timed release form.
Still on the natural vs. synthetic and bioavailability issues, there is another kind of supplement that you will sometimes come across that I will briefly discuss. These are usually called "food form" or "food matrix" supplements. The basic philosophy behind these products is that nutrients are better absorbed when they are part of an organic multi molecular matrix similar to how they occur in foods. Supposedly these kinds of supplements are made by force-feeding certain kinds of yeast large amounts of a particular nutrient in its synthetic form and forcing them to convert it to a more natural, organic form. An extract is then made of the yeast which includes these nutrients in a "food form" along with other cofactors found in the yeast. Although the basic idea sounds good, I do not recommend these kinds of supplements for several reasons. Firstly, it is difficult to guarantee that these products actually contain what they claim to contain. Some manufacturers have been know to simply mix synthetic vitamins with yeast or other food extracts, in which case the vitamins haven't really been converted to an organic form. This is particularly an issue in the U.S. where quality control standards are not as stringent as in Canada. So far I am not aware of any companies manufacturing these products in Canada and I have yet to see any of the American products with an NPN (Natural Health Product Number) indicating that they have met Canadian standards. Another concern is that sometimes nutrients of this kind are manufactured by genetically engineering yeasts or other organisms to produce the nutrient in large quantities as a metabolic by-product. Even for those products that are what they say they are, there is no independent research that I am aware of that indicates that this form of nutrient is more bioavailable. In fact, in order for nutrients to be absorbed they must be separated from any organic molecules to which they are attached. For this reason nutrients are usually better absorbed when they occur as closely as possible to their free form state. Finally, these nutrients tend to be a lot more expensive than standard vitamins and minerals even though they contain much lower doses of nutrients. The rationale for the lower doses is that they are supposed to be better absorbed. However, this isn't necessarily the case and even if it is, you are still going to absorb more from a standard supplement that contains a much higher dose - at a fraction the price! The bottom line is, even if some of these products contain what they claim to contain and work as well as they are supposed to, you will get a lot more value for your money purchasing other forms of supplements.
This is the end of my second post on this topic. In Part 3 I will continue this discussion and then explain what I personally recommend as a basic supplement regimen.