Recently, this magazine ran a series of articles on vitamin
and mineral supplements addressing the seemingly
simple question, “Who needs them?” This seemed
like a good jumping off point. Whenever you look at a
supplement, you ask yourself what benefits its various ingredients
will deliver. One formula promises to provide insurance against a
multitude of vitamin and mineral deficiencies, another to supply
protection against stress, and a third claims to protect against,
say, bone loss. Athletes, in particular, constantly push their bodies
“to the edge,” and they rightly expect ergogenic aids to be just
that—substances that improve the body’s capacity to engage in
physical activities. Moreover, serious athletes and body builders
often cross the line between training and over-training. Dietary
supplements are expected to a variety of needs, both minor and
major. However, is choosing a supplement merely a matter of
finding one with ingredients that match perceived needs?
If only it were that simple! All supplements work through
the metabolism of the body. This is the reason that good
formulators try to take the body’s metabolism into account
when designing products. At stake is the bioavailability of
nutrients. The absorption of nutrients involves at least three
steps: any supplement must first be digested, then assimilated,
and, finally, utilized. Increasing bioavailability may require the
manipulation of one or more of these factors.
Fortunately, there are steps that can be taken to improve
the bioavailability of nutrients. For convenience, these steps
can be described as aspects of digestion, assimilation and
utilization, although some aids to nutrient absorption actually
will be active in all three areas.
Let’s start with that can of expensive protein powder you
are consuming or the specialty minerals you take. Without
adequate production of hydrochloric acid and pepsin in the
stomach, neither the proteins nor the minerals will be well
assimilated. Probably 40 percent of all adults suffer from
too little stomach acid (hypochlorhydria).1 It is likely that the
majority of those who have frequent indigestion think they are
secreting too much stomach acid and reach for antacids for
relief when, in reality, their stomach’s secrete too little stomach
acid. Even individuals in apparent good health can bring on
digestive difficulties through food choices. Athletes who have
increased their protein intake dramatically or those who drink
large amounts of milk with meals have increased the demands
made upon their stomach’s digestive capacities. (Milk’s calcium
content tends to neutralize stomach acid and thus reduces the
stomach’s ability to digest protein.) If you suffer from bloating or
discomfort immediately after eating or feel nauseous after taking
supplements, you should explore the possibility that you are not
producing adequate hydrochloric acid.
Digestion starts in the mouth, continues in the stomach
and finishes in the intestines. Malabsorption syndromes are
usually problems that originate in the stomach and small
intestine and lead to a variety of nutrient deficiencies. Aside
from inadequate hydrochloric acid, chiefly involved in these
syndromes is the pancreas, the organ which secretes almost
one half gallon of pancreatic juice into the small intestine in
a 24-hour period. This fluid includes amylases to break down
starch into sugars, lipasesto aid in the digestion of fats, and
proteases to finish the digestion of proteins. Finally, bile, which
is produced by the liver and released by the gallbladder, aids
in the assimilation of fat-soluble vitamins and other nutrients
and helps to soften the stool to prevent constipation. A less
recognized fact is that, along with stomach acid, bile and the
proteases are the primary barriers to the infestation of the
gastro-intestinal tract by parasites and yeasts.
Quite a number of supplements can be used to improve
the digestive functions of the stomach. These include betaine
hydrochloride, pepsin, pancreatic enzymes, bromelain (from
the stem of the pineapple), papain (from green papaya fruit),
ginger, niacin, cayenne pepper, black pepper and its extracts,
etc. The most direct approach is to use hydrochloric acid
bound to betaine and mixed with pepsin in a ratio of 600 mg
betaine hydrochloride to 150 mg pepsin. Jonathan Wright, MD
suggests a regimen that starts with one tablet per meal. The
dosage is increased by one tablet at each subsequent large
meal until there is a feeling of slight warmth in the stomach
and then reduced by one tablet. No more than seven tablets
are taken at any given meal and the dosage is reduced if there
is discomfort. Once digestion improves, the dosage may need
to be reduced,2 as well. Various commercial preparations of
amylases, lipases, proteases, and other enzymatic digestive
aids are available and should be used according to package
directions. Plant sources of the enzymes include members
of the fungal family of Aspergillus. Other formulas contain
pancreatic enzymes derived from ox or porcine sources and
should have a United States Pharmacopoeia (USP) number of
1 × pancreatin or greater. Better sources run from 4 × to 10 ×
USP. Some authorities suggest that the USP value should be
as high as 10× and that 500 –1,000 mg should be taken before
each meal for best results.3
After digestion comes assimilation. This takes place primarily
in the small intestine. Just as with digestion, many factors
can adversely affect assimilation. Some nutrients can only be
assimilated within the first foot or so of this intestine, whereas
others can pass into the blood stream along almost the entire
length of both intestines. Some nutrients interact badly or
compete for absorption. Others require that your body secrete
special proteins as carriers before they can be absorbed.
Vitamin B-12 requires a substance secreted by the stomach
in order to be absorbed, whereas folic acid requires a substance
secreted by the small intestine. Fat soluble vitamins, including A, D, E and K, all are best absorbed when taken with meals which contain some fat or oil. Sometimes strictly digestive enzymes are
included in formulas to improve absorption as well as digestion,
but the verdict on these is mixed. Bromelain is probably the best
known of the enzymes used for this purpose. The claim made
for it, i.e., that it improves the uptake of nutrients, is based on
a limited number of studies which seemed to show that some
antibiotics were better assimilated when taken along with this
protein-digesting enzyme. Whether bromelain gives similar
benefits in the cases of nutrients has never been studied.
Nevertheless, quite a number of items do increase
assimilation substantially. These include glucosamine,
piperine, and forms of lecithin, especially lyso-lecithin. Perhaps
the biggest surprise here is the first item. Glucosamine today
is particularly noted for helping in the repair of arthritic joints.
However, United States Patent 2,907,697 was granted back in
1959 and covered the employment of glucosamine (in various
forms) to enhance the absorption of vitamin B-12. The way
in which glucosamine works to enhance absorption has not
been fully understood, but we know now that glucosamine,
especially in the form of N-acetyl-glucosamine (NAG) greatly
improves the health of the mucosal membranes of the
intestines.4 Inasmuch as glucosamine likely works by a general
mechanism, taking 1–2 grams along with your most important
nutritional compounds may be worthwhile. NAG, also
available in a special form called Poly-NAG, is beneficial to the
gastro-intestinal tract under all circumstances. Glucosamine
hydrochloride similarly may be used for this purpose.
Piperine is an active principle extracted from black pepper.
Approximately 5 mg of almost pure piperine administered at
the same time as other nutrients (selenium, beta-carotene and
vitamin B-6) resulted in increased absorption ranging from 30
to 250 percent in trials.5 Although there is some controversy on
this point, capsaicin, the “hot” compound found in cayenne
and related peppers, while improving the digestion of some
foods, may not improve nutrient bioavailability in the same way
as piperine.6 Piperine must be taken at the same time as the
nutrients to be assimilated if there is to be any benefit.
Now for the champ in the category of assimilation: Lecithin,
phosphatidylcholine, polyenylphosphatidylcholine (PPC) and
related compounds, all grouped broadly under the heading
“phospholipids,” typically help to improve liver function and
to increase the solubility of bile. This means these compounds
aid in the absorption of fat-soluble nutrients. However,
this is not the most interesting aspect of lecithin. When we
eat lecithin, small amounts are changed into lysolecithin
(technically, lysophosphatidylcholine) in the small intestine.
How much depends upon the type of lecithin consumed. For
instance, eggs, which contain substantial amounts of lecithin
in their yolks, traditionally have been considered to greatly
improve the absorption of nutrients. Lysolecithin alters the
permeability of membranes and thereby increases the uptake
of nutrients. To put this differently, lysolecithin “changes the
size of the holes” in membranes.7 Subject to a United Kingdom
Patent, lysolecithin was first found to increase food efficiency
in animals. Improvements in nutrient assimilation were about
30 percent for a broad range of minerals and amino acids.
Lysolecithin has been further developed as a human weight
gain supplement and even has been used to help lactating
mothers produce more milk for their infants.
Dosage in the case of lysolecithin is important because,
unlike other forms of lecithin, one can ingest too much
lysolecithin. The standard recommendation of pure lysolecithin
is 1 to 100 mg per kilogram (2.2 pounds) of total food intake.
Commercial preparations vary dramatically in purity, so it is an
excellent idea to follow directions closely.
Very interesting is the impact of probiotics on the availability
of nutrients, particularly the minerals magnesium, iron and
zinc, from grains. This is true of the bread-making process,
sourdough preparations improving nutrient bioavailability over
normal processes, but also perhaps for the use of probiotic
supplements.8 There is the additional benefit of inhibiting the
growth and adhesion of enteric and foodborne pathogens.9
After assimilation comes utilization. This is a complex issue
that can only be touched upon here. It is known that many
nutrients facilitate the actions of other nutrients. A deficiency
of zinc, for instance, makes the use of vitamin A in the body
more difficult. The consumption of a small amount of alcohol
greatly improves the assimilation of many substances, but
in large amounts alcohol not only is toxic itself, but it also
prevents the body from using nutrients, such as beta-carotene,
or causes the loss of nutrients, such as magnesium. Again,
there appears to be a synergism between nutrients such as
selenium and vitamin E or many of the bioflavonoids and
vitamin C. Flax seed oil and other sources of essential fatty
acids may be more effective if eaten with proteins. Therefore,
be aware that balance and synergism are necessary for the
proper use of nutrients by the body.
Piperine, already discussed for its ability to increase
nutrient uptake, inhibits the breakdown of many compounds
in the body, yet also protects against the production of certain
classes of toxic compounds in the body by cytochromes P-450.
The same mechanism which prevents the rapid destruction
of many compounds that we would consider to be beneficial
prevents drug metabolizing enzymes from activating toxins,
such as aflatoxin B.10
An alternate approach to getting more from your nutrients
is to look to the health of your liver. If the liver is not working up
to par, eating extra protein, for instance, may lead to increased
levels of ammonia in the body, and this will damage your ability
to recover from workouts. Moreover, many nutrients must be
transformed into coenzymatic forms in the liver before the
body can use them. Classic liver supporting nutrients and
herbs can be very helpful. These include choline (1 gram/day),
polyenylphosphatidylcholine (PPC), L-carnitine (1,000 mg twice
per day), and the extracts of dandelion, milk thistle and artichoke.
- Gastroenterology May 1946: 348–352; British Journal of Medicine 1930; i: 1–14.
- Wright JV. Dr. Wright’s Guide to Healing with Nutrition. Keats Publishing, New Canaan, CT, 1990: 30–50.
- Whitaker J. Dr. Whitaker’s Guide to Natural Healing. Prima Publishing 1995: 69–72.
- American Journal of Gastroenterology1983; 78: 19–22.
- Nutrition Science News March 1996; 1, 1: 36–8.
- Critical Reviews in Food Science and Nutrition 1991; 29: 435–74.
- The Genetic Engineer and Biotechnologist 1993; 13, 2: 95 –104.
- J Anim Sci. 2010 Oct;88(10):3320–6.
- J Food Sci. 2010 Nov-Dec;75(9):M546-51. doi: 10.1111/j.1750-3841.2010.01818.x. Epub 2010 Oct 7.
- The Journal of Pharmacology and Experimental Therapeutics 1985; 232, 1: 258–62; Cancer Letters 1994; 86:195–200.