There has been a tremendous amount of controversy lately, swirling around the various nutritional circles I am connected to, involving the supposed toxicity of vitamin A and one of its most potent nutritional sources- cod liver oil.
The topic was first brought to light after early research showed an increase in fracture rates and osteoporosis risk from excessive vitamin A intake. However, additional studies in 2005 and 2009 seem to have discredited the original findings, suggesting there was no connection between the two.
More recently, the Vitamin D Council came out with a statement again suggesting that vitamin A can indeed be toxic and that cod liver oil should be avoided. This article suggested that while cultures around the world who are deficient in vitamin A certainly benefit from taking it, more affluent cultures like ours have no such deficiency and cited studies showing that taking additional amounts could be harmful.
An article by Dr. Joe Mercola followed soon afterwards, echoing the statements made by the Vitamin D Council. In this article Dr. Mercola, a long-time proponent of cod liver oil, completely reversed his stance based on the findings reported by the Vitamin D Council, suggesting we all avoid it from now on.
Finally, the Weston Price Foundation, another long time supporter of cod liver oil consumption, had previously published articles supporting the use of vitamin A and refutting the vitamin A-osteoporosis connection. They then came out with a preliminary rebuttal to the statements by Mercola and the Vitamin D Council and plan to publish a more in depth article exploring this topic further in the next edition of their journal.
The problem with all of this is that these three groups, especially Weston Price and Mercola.com have been some of the main influences in my nutritional education and research. Having also been a long time consumer and supporter of cod liver oil, I was (for lack of a better term) FREAKING OUT a bit when I read all the recent information from Mercola and the Vitamin D Council.
After taking a few breaths, researching more on my own, re-reading the article by the Vitamin D Council and contacting Dr. Mercola, Sally Fallon (president of the Weston Price Foundation), Dave Wetzel (owner of Green Pasture- the company who makes the cod liver oil I take and recommend to my patients) and Dr. Ron Schmid (owner of DrRons.com and long time cod liver oil advocate) all directly, I was finally able to revise my opinion on this entire topic. The remainder of this post will contain my best effort at summarizing my current stand on things.
Basically when it comes to vitamin A or cod liver oil my feelings are the same as they are when considering any other vitamin or supplement. In essence, natural and whole is better and safer than processed, isolated or synthetic.
What quickly became apparent to me when re-reading the information from the Vitamin D Council is that they kept referring to "modern cod liver oil" as being a problem. I would agree whole heartedly with this contention. You see, "modern cod liver oil" is not fully natural or whole. It is processed, molecularly distilled, heated, and basically altered in many ways from it's original form. It's difficult to say just how much all of these actions do to change its constituents, but one thing is for sure. The processing many cod liver oils go through significantly reduces their vitamin D levels. In turn we are left with a product that has much LESS vitamin D than whole, unprocessed cod liver oil does.
This brings me to my second point. As seems to be the case in other categories of nutrition and life in general, with vitamin A, vitamin D and cod liver oil, it's really all about balance. It's pretty well established that both vitamin A and D are essential nutrients for us. The problem comes when we over consume one over the other. Typical store bought cod liver oil, having been through all the processing it has, has less vitamin D than it should, thus decreasing its ratio in comparison to vitamin A. This is where I along with other experts I have spoken with feel the problem truly lies. Most cod liver oil brands are, in fact, unsafe, because they contain too much vitamin A compared to vitamin D.
In fact, some experts in the field have already come out in direct opposition to the Vitamin D Council's statements about cod liver oil, stating that they were making sweeping generalizations and, in essence, throwing the baby out with the bathwater!
Thankfully, all this time I have been recommending a brand of cod liver oil to my patients that is not nearly as highly processed, and still contains the natural ratios of vitamin A to vitamin D in it. I have also taken to recommending many of my patients take additional vitamin D during the winter time. I feel these steps have eliminated the risks proposed by the Vitamin D Council and Dr. Mercola.
Remember, cod liver oil has been used to complement traditional diets throughout the world for centuries. Traditional diets centered on foods rich in vitamins A and D – liver and other organ meats, seafood and the fats of grass-fed animals. People spent much more time outdoors in the sun than we do. Yet these people still used fish liver oils as an essential part of their diets.
The basic fact then is that extensive evidence shows natural vitamin A in foods such as cod liver oil is not toxic except in cases where vitamin D is deficient. The key is to avoid cod liver oil that contains low levels of vitamin D in relationship to vitamin A. The natural ratio is about ten to one, yet in some brands the ratio is as high as one hundred to one.
I have even come to find out that soon the company I get cod liver oil from for my patients (greenpasture.org) will only be carrying a fermented version of cod liver oil, the most truly natural form of all. Fermented cod liver oil not only contains the appropriate ratio of vitamin A to vitamin D, it is also easier to digest than regular cod liver oil, and contains a variety of other known and unknown nutrients produced directly via the fermentation process (see below for more details). Fermented cod liver oil is indeed one of nature's true super foods.
Finally, in all this discussion about vitamins A and D, something very important has been left out. Vitamin K. More specifically vitamin K2, the form of vitamin K found only in certain fermented foods and certain animal foods. Vitamin K1, found in plants and grasses, is not nearly as useful to us humans as K2 is now being found to be. Research is now showing K2 to be crucial for cardiovascular and bone health. Some research is now showing evidence that consuming it may even reduce plaque formation already present in a person's arteries!
It is my belief that we must eat a good balance of all three of these fat soluble nutrients- A, D and K, and that doing so will keep us safe from any potential toxic effects over consuming any one of them may cause. If we consume a traditional diet rich in high quality animal foods and the fats they naturally come with, and we are sure to get into the sun regularly, whenever we are able, we will get substantial, live-giving portions of all three of these nutrients.
Vitamin A can be found in beef and chicken livers, high quality, full fat dairy foods and fish liver oil. It's precursors-the carotenes are found in dark colored (especially reds and oranges, but also dark green) vegetables. If you are not a fan of organ meats, you can take these items in capsule or powdered form like I do.
The best source for vitamin D is sunshine. If that is not available and/or you live at a latitude where in the winter you can't make vitamin D from the sunshine no matter what, the next best source in my opinion is a vitamin D lamp. The third best option is old fashioned, fermented cod liver oil and straight vitamin D supplements. Again, if the vitamin D lamp is not an option for you, I recommend consuming both fermented cod liver oil and extra vitamin D during the winter (preferably emulsified).
The best sources of vitamin K2 are the traditional Japanese fermented food natto, raw fermented cheeses, raw butter and egg yolks. Interestingly enough, another way we are designed to obtain vitamin K2 is through the fermentation process that is supposed to be going on naturally in all of our guts. You see we are all supposed to have a high level of probiotic organisms in our guts, some of whom actually make vitamin K2 for us to absorb, when they ferment the vegetables and other healthy foods we are supposed to be consuming every day.
Unfortunately, many of us either don't eat the foods these bugs want to ferment, or we've done too many things like take antibiotics, prednisone and birth control pills, all of which destroy these precious friends of ours.
So the bottom line in all of this again is two fold:
1) Consume things in their most natural, unprocessed states.
2) Consume a balanced amount of ALL the nutrients needed for health, especially the fat soluble vitamins A, D and K.
This is obviously a vast topic and there is even more to it all than I am able to get down on a single blog posting. I've already gone way longer than usual! So, if you'd like to know more about this truly crucial component of nutrition and health, please contact me.
Tuesday, January 13, 2009
Cod Liver Oil, Bugs, Organs and Sunshine- Key Factors in Your Health
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4 comments:
When you say the ratio is 10:1 is that 10 for Vit A and 1 for Vit D?
My cod liver oil has 950iu of A and 20iu of D. Way more than 10:1.
Hi Sue,
Sorry for the tardy response. You are right- 10:1 means vitamin A to vitamin D. The ratio in yours is way to high for Vitamin A.
I know this is an older post, but I'm curious--I take both Blue Ice FCLO (approximately 2 ml/day) and take 2-6 Liver pills from Dr. Rons daily. Should I be supplementing with Vitamin D to account for the additional Vit A in the liver pills? I read somewhere that dried liver pills don't have the fat soluble vitamins since the fat is trimmed? Not sure that's true--I live in Oregon, so not much year round Vit D from the sun. I eat a balanced diet that includes farm fresh eggs, raw goat's milk, butter, beef/chicken/pork all from local sources, organic fruits and veggies, bone broths and some high vitamin butter. We are soon to start trying to conceive our first child and there's so much conflicting advice on CLO/Vitamin A/Liver consumption for pregnancy--it's really frustrating! Is 2-4 ml FCLO and Liver pills too much? I'm following much of the advice of WAP.
Some of the cod liver oil problem came about as a result of some European rules. Fortunately, there were companies like Carlson's and Nordic Naturals that chose proper production. International production standards allow a company to call their product "cod liver oil", even if it is fish body oil (typically haddock or pollock), as long as it matches the EPA:DHA ratio. These products are generally supplemented with (natural or synthetic) vitamin A. I would stick to Carlson's or Nordic Naturals. Sonne's looks like it is unheated, unprocessed cod liver oil, as well.
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