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.
Why Sunlight is Your Best Source of Vitamin D (11/08 mercola.com)
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 flu.
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.
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.
Why Sunlight is Your Best Source of Vitamin D (11/08 mercola.com)
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 flu.
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.