The Dangers Of Cod Liver Oil With Vitamin D
Sixteen well-known experts, including professors Walter Willett and Ed
Giovannucci of Harvard, Dr. John Hathcock of the Council for Responsible
Nutrition, and Professor Reinhold Vieth of the University of Toronto, published
an unprecedented warning about the ingestion of cod liver oil and resultant
vitamin A toxicity.
Using the strongest language published to date, the group condemned the current
(1997) Food and Nutrition Board (FNB) recommendations for vitamin D, stating
"The 1997 FNB recommendations offend the most basic principles of pharmacology
and toxicology, leading us to conclude that the current official guidelines and
limitations for vitamin D intakes are scientifically indefensible."
In addition to warning about the consumption of cod liver oil, the above experts
recommended healthy children take 1,000 IU/day of vitamin D for every 25 pounds
of body weight. In some cases this is more than ten times current
recommendations for children by the government and professional organizations.
Finally, the group recommended that "children with chronic illness such as
autism, diabetes, and/or frequent infections" may need to take even more
vitamin D, "doses adequate to maintain their 25-hydroxy vitamin D in the mid
normal of the reference range (65 ng/ml) - and should be so supplemented year
around." Less than one percent of American children currently have such levels.
Cod Liver Oil, Vitamin A Toxicity, Frequent Respiratory Infections, and the
Vitamin D Deficiency Epidemic (11/08) published by John J. Cannell, MD;
Reinhold Vieth, MS, PhD; Walter Willett, MD, DrPH; Michael Zasloff, MD, PhD;
John N. Hathcock, MSc, PhD; John H. White, PhD; Sherry A. Tanumihardjo, MSc,
PhD; D. Enette Larson-Meyer, PhD; Heike A. Bischoff-Ferrari, MD, MPH; Christel
J. Lamberg-Allardt, PhD; Joan M. Lappe, PhD, RN; Anthony W. Norman, PhD; Armin
Zittermann, PhD; Susan J. Whiting, MSc, PhD; William B. Grant, PhD; Bruce W.
Hollis, PhD; Edward Giovannucci, MD.
According to one of the writers, John Cannell, MD (Vitamin D Council), the key is having the proper ratio of vitamin D to vitamin A in your body, is
to obtain this proper D/A ratio, you must make a choice. (1) Either obtain the
D/A ratio Nature and God intended, that is, the ratio the human genome evolved
on, or (2) think you know everything, intervene in a closed system, bypass the
controls in the intestine and inject active A directly into your blood by
taking vitamin A or cod liver oil. Vitamin A production is tightly controlled
in the body, the source (substrate) being carotenoids from vegetables in your
intestine. The body uses these carotenoid substrates to make exactly the right
amount of retinol for your body. That is, it is a closed, tightly regulated,
system, one designed to perfection by God and Nature. When you take vitamin A
as retinol, such as in cod liver oil, you intervene in this closed system and
bypass the controls. Proceed at your peril.
Vitamin D is also a closed controlled system and I don't recommend intervening
in that system either. Vitamin D is a substrate, like carotenoids, it is not
the active substance. Taking vitamin A as retinol is like taking activated
vitamin D, calcitriol. Doing so bypasses controls and I have never recommended
anyone take activated vitamin D except patients with renal failure under the
care of a nephrologist. As long as your vitamin D dose is not excessive, you
are not intervening in a closed system, you are simply providing the vitamin D
substrate. The body, if and when it has enough vitamin D substrate, will use
what it needs and dispose or store the rest.
Thus the goal is to provide all the vitamin A and vitamin D substrate the body
would have obtained in a natural state, so the body can regulate both systems
naturally. This is best done by eating colorful vegetables and by exposing your
naked skin to equatorial sun every day. Since most of us can't do the later,
and won't do the former, we have to take the same amount of vitamin D substrate
we would have gotten if we lived 100,000 years ago, and may want to take
beta-carotene substrate in a multivitamin. As far as I know, low doses of
beta-carotene (1,000 to 2,000 IU per day) will not do too much harm. The best
way to get vitamin D substrate, as far as I can tell, is to take about 1,000 IU
of vitamin D3 per every 25 pounds of body weight in the winter and stop all
vitamin D in the summer and sunbathe. Alternatively, use a tanning bed when the
sun is to low on the horizon to sunbathe. Remember, when you are outside, if
your shadow is longer than you are, you are not making any vitamin D.
A 2004 study seemed to show that vitamin D in the form of cod liver oil had only
a mild effect on reducing upper respiratory tract infections in young children.
This result was surprising, considering that it has been known since at least
1926 that vitamin D can significantly reduce respiratory infection, colds, and
In fact, vitamin D plays a pivotal role in the immune system. The explanation
likely comes from the fact that vitamin D in cod liver oil does not exist in
isolation -- it comes with a high dose of vitamin A. Vitamin A and vitamin D
compete for each other's function. For example, even the vitamin A in a single
serving of liver can impair vitamin D's rapid intestinal calcium response.
Unfortunately, Americans tend to consume multivitamins or cod liver oil that
contain disproportionately small amounts of vitamin D, but detrimental
quantities of vitamin A. One manufacturer sells cod liver oil containing only 3
to 60 IU of vitamin D, but between 3,000 and 6,000 IU of vitamin A.
A separate study by Daniel Hayes, Ph.D., of the New York City Department of
Health and Mental Hygiene also suggests that a form of vitamin D could be one
of your body's main protections against damage from low levels of radiation.
Hayes explains that calcitriol, the active form of vitamin D, may protect us
from background radiation and could be used as a safe protective agent before
or after a low-level nuclear incident. He points out that calcitriol is
involved in cell cycle regulation and control of proliferation, cellular
differentiation and communication between cells, as well as programmed cell
death (apoptosis and autophagy) and antiangiogenesis. Calcitriol is the form of
vitamin D that activates your body's Vitamin D Receptor (VDR), which allows
gene transcription to take place and the activation of the innate immune
response. It is possible that several of the transcriptions by the VDR will
help transcribe proteins that protect the body against radiation.