I subscribe to online health tips from Dr Chaney.
I want to share his most recent post with you as
I believe we need to be as informed as possible
when making decisions regarding our health.
Healthy Blessings,
Cheryl.
***************************************
A lot of you have been asking me about recent headlines
claiming that use of multivitamins and selected
vitamins or minerals may increase the risk of mortality
- and that supplemental calcium use may decrease
the risk of mortality.
Some of the headlines have gone as far to say that
vitamins can kill you.
What is the truth? Should you throw those vitamins
and minerals away, or are they safe for you to use?
The answer is -
some are and some aren't.
First let me start with a brief description of
the study and the results (Mursu et al, Archives of
Internal Medicine, 171: 1625-1633, 2011).
The data for this report were obtained from the
Iowa Women's Health Study. 38,722 older women (average age
61.6, range of ages = 55 to 69) were enrolled in the
study and followed for 19 years.
The women enrolled in the study filled out
extensive questionnaires in 1986, 1997 and 2004 that provided
information on their diet, lifestyle, health and
supplement intake.
The supplements evaluated on the questionnaire were
multivitamins and individual B complex, A, beta-
carotene, B6, folic acid, C, D, E, calcium,
copper, magnesium, selenium and zinc supplements. Supplements
like omega-3 fatty acids, probiotics and polyphenols
were not included in this study because their health
benefits were not recognized in 1986.
During the 19 years covered by the study, 15,594 of the
women (40.2%) died.
When the data were adjusted for age and calorie intake
use of B complex, C, D, E and calcium supplements were
associated with a slightly lower risk of death and
supplemental copper intake was associated with a
significantly higher risk of death than non-supplement
use.
When the data were further adjusted for medical
conditions and lifestyle differences between the
two groups at the time of entry into the study supplemental
calcium intake was associated with a decreased risk of
death, use of multivitamins and supplemental B6 or iron
were associated with a slight increased risk of
death and use of copper supplements was associated with a
significantly increased risk of death.
And when the data were even further adjusted
for dietary differences between the two groups,
supplemental calcium intake was still associated with a
decreased risk of death, use of multivitamins and
supplemtal B6, folic acid, magnesium, zinc or iron
were associated with a slight increased risk of death and
use of copper supplements was associated with a
significantly increased risk of death.
In analyzing any study like this the best place to
start is to analyze its strengths and weaknesses.
Its strengths are obvious. It is a very large study and
it followed people for a long time (19 years).
However, its weaknesses are many:
1) As the authors have admitted, it is an observational
study and does not prove cause and effect.
In non-scientific language, this means that this study
does not prove that vitamin use increases the risk of
death, only that it is associated with increased risk
of death under the particular conditions of
the study. Thus, it is important to carefully examine the
conditions of the study to see if there are confounding
factors that might have contributed to the results.
2) The data initially showed an increased risk of
death only associated with copper intake. It had to be
extensively massaged before any other adverse
associations became apparent.
3) The authors also observed that several of their
conclusions were not supported by previous studies.
Again, when you see this kind of discordance
between one study and several previous studies, further studies
should be performed to confirm or refute the results of
the study before recommendations are made to the
general public.
And when this kind of discordance arises, it is also
important to examine possible confounding
variables to see if there are some unique variables that may
have contributed to the results of the study.
In my opinion, there are at least two confounding
variables that merit further evaluation.
3a) While the vitamin users had slightly better diet
and lifestyle than the non-supplement users, those
differences were fairly small.
However, the use of estrogen hormone replacement
therapy was almost twice as prevalent in the supplement users
than the non-users. That is a concern because use of
hormone replacement therapy is known to be associated
with a significantly increased risk of death in this
population group.
Although an attempt was made to adjust for estrogen
use, Ithink that further studies are needed to see if
hormone replacement therapy has skewed the results of
this study.
3b) The percentage of women using supplements almost
doubled during the course of the study and the
"supplement group" included both the women using
supplements at the beginning of the study and the women
who started supplement use during the study.
As the authors noted this raises the possibility that
the supplemented group may have included a significant
number of women who started using supplements because
of medical conditions that arose during the study.
Ideally, the supplement using group and the non-
supplement using group should both be disease free at
the time supplement use was initiated if you are going
to have a valid comparison.
4) The sample size was extremely small (108-530) for
some of the groups where adverse effects were reported
- especially copper, vitamin B6 and folic acid.
5) The study only reported supplement use versus non-
use. It did not report the dosage of the individual
supplements used by the women in the study. This is
critical information, because both iron and copper
are known to be toxic - and magnesium and zinc have the
potential to be toxic - when used as stand-alone
supplements at high doses.
6) This brings me to my most important critique. This
study evaluated individual, probably high dose
supplements. This is a concern because individual
high dose supplements can cause harm by interfering with the
absorption of similar nutrients from food or multivitamins.
As an example, this study reported that use of
individual B6 or folic acid supplements were
associatedwith a higher risk of mortality, but a B complex
supplement containing B6 and folic acid (along with the
other B vitamins) had no effect on mortality.
Next week (see Killer Vitamins --Part 2 below) in part two of this series I will discuss
my "bottom line" recommendations for you based on an in-
depth analysis of this study's results and other pertinent literature.
##########################################################
KILLER VITAMINS -- Part 2
Last week I discussed the strengths and weaknesses of
the Iowa Women's Health Study (Mursu et al, Archives of
Internal Medicine, 171: 1625-1633, 2011) which has been
interpreted as suggesting that multivitamins and
certain individual vitamin or mineral supplements could
actually increase the risk of mortality in older women.
This week I'd like to focus on the bottom line for you,
and give you my personal recommendations.
1) As I mentioned last week the sample size for women
taking a copper-only supplement was exceedingly small
(108), so I do not have much confidence in the data
reported for copper supplement users in this study.
However, high doses of copper can be toxic and there is
no reason to be taking a stand-alone copper supplement
unless it is recommended by your physician.
On the other hand, copper is an essential nutrient, so
some copper should be included in your multivitamins. I
recommend looking for multivitamins providing around 1
mg of copper (50% of the DV) on a daily basis.
2) The potential toxicity of iron in adult men and
post-menopausal women is well documented. About 5-10%
of these population groups have an increased need for
iron that can be easily diagnosed by their physicians.
There is another 10-15% that have a genetic condition
that can lead to iron overload and premature death.
This condition is insidious and is often not diagnosed
until considerable damage has been done. For the rest
of the people in these population groups iron offers
neither a risk nor a benefit.
This is why the standard recommendation for adult men
and post-menopausal women is to avoid iron supplements
and iron-containing multivitamins unless supplemental
iron is specifically recommended by their physicians.
To be quite clear, if you are an adult man or post-
menopausal woman there is no reason to be taking an
iron-containing supplement unless it has been
recommended by your physician.
3) The potential toxicity of vitamin B6 and folic acid
as stand-alone supplements in this study was quite
small and was not seen in several previous studies.
However, as I pointed out last week there was no risk
involved in taking a B complex supplement containing
B6 and folic acid.
This reinforces a continuing theme of mine - namely
that we should be focusing on a holistic, balanced
approach to supplementation rather than relying on
supplements providing individual, high potency
nutrients.
4) Similarly, the potential toxicity of magnesium and
zinc was also quite small, was seen only after
considerable adjustment of the primary data, and has
not been seen in several previous studies.
My recommendation would be to get both of these
nutrients from a well-designed multivitamin supplement
where all of the essential minerals are provided in the
appropriate amounts and balance. If you do use
magnesium and zinc as stand-alone supplements my
recommendation would be to avoid very high doses of
either unless directed by your physician.
5) The very slight increase in mortality associated
with multivitamin use is not completely surprising
because some previous studies have suggested this
posiblity.
As last week one needs to know why the participants
were taking a multivitamin (ie, was it because they had
a medical condition) to appropriately evaluate these
data.
However, it is also important to ask how well designed
and tested the multivitamin was. There are some
multivitamins in the marketplace that are so poorly
designed and/or manufactured that they could possibly
cause more harm than good. Here are the questions
that you should ask about the supplement that you are
using:
- Does it represent a holistic approach to
supplementation?
I have already talked about the value of having all of
the B vitamins in balance rather than high dose B6 or
folic acid alone. However, both pure alpha tocopherol
alone (even all natural d-alpha tocopherol) or pure
beta- carotene alone have the potential to cause some
harm by interfering with the absorption of similar
nutrients.
You should look for a supplement that provides all of
the naturally occurring tocopherols and tocotrienols -
especially gamma-, beta- and delta tocopherol rather
than pure d-alpha-tocopherol alone.
You should also look for a supplement that provides all
of the major carotenoids (beta-carotene, alpha-
carotene, lycopene, lutein, and zeaxanthin) rather than
beta-carotene alone.
And finally, a truly holistic supplement will contain
omega-3 fatty acids, polyphenols and probiotics.
- Does the manufacturer do quality controls that
guarantee the supplement does not contain contaminants
that can harm you? Ask them how many quality controls
they perform with the product that you are using.
- Can the supplement manufacturer provide you with
clinical studies done with their product showing that
it delivers the nutrients to your bloodstream and has
the intended effect in your body? Animal and cell
culture studies don't count.
- Are there clinical studies showing that long term use
of the supplement actually decreases disease risk? The
study should be at least as long as the Iowa Women's
Health Study (19 years).
6) Finally, we should not ignore the "good news" part
of the study - namely that calcium supplementation
decreased mortality risk. Of course, this conclusion is
subject to the same limitations as the previous ones
and not every previous study has come to the same
conclusion.
The DV for calcium for women in this age range is 1,200
mg/day and some 40-60% of older women do not achieve
this from diet alone. I recommend that everyone strive
for the DV for calcium from diet plus supplementation.
Intakes slightly above 1,200 mg/day are probably safe
for older women, but I don't recommend going above
2,000 mg/day.
I've covered a lot of ground over the past two weeks.
Let me close with a quick summary.
- The Iowa Women's Health Study has a number of
significant design flaws and its conclusions should be
confirmed by subsequent studies before recommendations
are made to the public.
- The study's warning against taking iron-containing
supplements and copper-alone supplements is, however,
right on. In postmenopausal women these supplements
should only be taken if prescribed by a doctor.
- Individual high dose B6 or folic acid supplements are
also probably not a good idea unless prescribed by a
physician, but a well designed B complex or
multivitamin supplement containing those nutrients
appears to be safe.
- The risk associated with individual high dose
magnesium and zinc is weak and needs to be confirmed by
additional studies. Holistic supplements containing
magnesium and zinc should not be a problem.
- The risk associated with multivitamin use was also
weak and needs to be confirmed. My take on this is that
many of the multivitamins on the market are poorly
designed and could conceivable cause more harm than
good. I recommend looking for holistic supplements
backed by strong clinical studies showing that they are
safe and effective for long term use.
- This study suggests that supplemental calcium may
decrease the risk of death. While this needs to be
confirmed by subsequent studies, it does make sense to
make sure that you are getting the DV for calcium on a
daily basis.
To Your Health!
Dr. Stephen G Chaney
Shaklee Master Coordinator
*These statements have not been evaluated by the Food
and Drug Administration. This information is not
intended to diagnose, treat, cure or prevent
any disease.
****ABOUT DR CHANEY:
Dr. Stephen Chaney, Phd
Dr. Chaney has a BS in Chemistry from Duke University
and a PhD in Biochemistry from UCLA. He currently holds
the rank of Professor at a major university.
Dr. Chaney has taught biochemistry to medical and dental
students for more than 30 years and has won several awards
for teaching excellence.
He runs an active cancer research program and has published
over 100 scientific articles and reviews in peer-reviewed scientific
journals. He has also written two chapters on nutrition for a
popular medical biochemistry textbook.
Dr. Chaney and his wife have also built a business part time that
has earned them a 6 -figure income for the past 15 years and he
has spent the last 10 years teaching other people how to do the same.
[If you want more information about Shaklee supplements,
please check out my website at www.babyboomerhealth.myshaklee.com]
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