This Vitamin A, D and K issue (VA, VD, VK from here on out) has gotten heated in a few circles. My recommendations on the topic have been based in large part on Prof. Cordain’s recommendations, and his thoughts were extensions of some work indicating a potential antagonistic action of VA against VD. This has created some kind of Cod Liver Oil Vs The World kinda scenario that I think is missing the point.
Let’s back up from this a minute and consider a few things:
1-Who are you? What are YOUR needs?
This is not some kind of existentialist question but more a question of health status. Many people entering into this whole Paleo-esque lifeway find they have significant levels of inflammation. Often evidenced by pain, swelling, overweight, allergies and sometimes more significant problems. Dietary recommendations focus on pushing out pro-inflammatory, gut irritating grains, legumes and diary in favor for meats, sea food, and seasonal fruits and veggies. Ideally, a solid NUTRITONAL base is formed and folks start looking, feeling and performing better almost immediately. In an effort to speed this process supplemental fish oil is often recommended to help folks cool the fires of inflammation via increased N-3 (Omega-3) fat intake. This is particularly important for people who have been quite sick, inflamed or who are overweight. The standard western diet unfortunately over emphasizes sources of short chain N-6 (Omega-6) which are pro-inflammatory. So folks may find themselves benefitting from taking rather large doses of fish oil. Like 20-30g of EPA/DHA per day for some folks, at leas initially. That’s a lot but it’s spot on for certain situations. Now, what type of N-3 source should one use? If you are a health educator, gym owner or other person who works with the public what makes the most sense to recommend in this situation? Many folks have contacted me on this VA/VD issue who seem to be BIG fans of the Weston Price Foundation. I like WPF, but I have some points of disagreement, but in large part I like what they have going on. Most of these folks through (WPF) recommend using cod liver oil (CLO) for supplemental N-3 as well as VA/VD. Well, let’s look at one of my favorite products, Carlson’s Cod Liver Oil. Now, from the nutrition info we see that a teaspoon of CLO provides 900mg of EPA/DHA, 800IU VA, 400 IU VD. So, in my example above, of a person new to all these concepts, who is trying to get healthy and is recommended they take CLO for their N-3 needs they will be ingesting more than 20-30x that single dose of VA/VD.
At 20g it’s 18,888 IU VA.
At 30g It’s 28,333 IU VA
Obviously the VD levels are ~half those the VA, ~9,000 and 13,500 respectively. Now this LOOKS like a whopping dose of VA, and it’s not shabby. Are there any toxicity issues here? Not likely. But it’s a hell of a dose that has no feedback control, unlike getting VA from carotenoids. Although the “Upper Limit” is set at ~10,000 IU this is for AVERAGE people. The folks who are taking this much fish oil are overweight and I’d wager have a pretty large buffering capacity to deal with that extra VA. As they lose weight and get healthier they will lower their dose and thus decrease intake of VA/VD. But are YOU comfortable with recommending a borderline toxic dose of VA? Do you recommend “some CLO” and “some fish oil”? What’s YOUR easiest, best, safest recommendation here?
A few studies seem to indicate VA might be antagonistic towards VD. In response to this information Cordain, myself and some other folks have recommended that perhaps one should supplement with fish oil and VD (ideally from sunlight), and leave the VA to production from carotenoids.
Many folks have said this approach is ineffective due to a “lack of conversion of carotenoids to VA”. There are studies that indicate a wide variance in absorption/conversion of carotenoids to VA, but no mechanism is described. A little digging shows (shockingly) that deficiencies in VA and VK might be best attributed to gut irritation ala celiac. Interestingly however celiacs appear to absorb carotenoids BETTER than VA when the gut is irritated. Not just this, but a TIGHT control mechanism is in place that immediately down-regulates the conversion of carotenoids to VA upon the ingestion of carotenoids. You folks who have dismissed carotenoid conversion to VA as being “negligible” have missed the boat. We would not have a mechanism in place such as this if the system did not require tight control. Also, you folks have made the point these carotenoids “need to be associated with fat”. Considering this is coming from the WPF corners I cannot believe one of y’all have considered the input of animal fat associated carotenoids. Keep in mind this is only considering Beta carotine, there are several other carotenoids that can convert to VA, and this is only considering the MEAT, not the rendered fat which would supply larger amounts of carotenoids. In simple terms, the only problem I see with VA production is if the gut is damaged. Keep this in mind.
Chris Masterjohn has written quite a bit on the VA/VD/VK topic and seems to indicate that this whole situation is remedied when we have a BALANCE of vitamins A, D, and K! Another interesting piece to the whole picture: Vit K absorption is highly dependant on gut health (primary sources are green leafy plants), as is the fermentive production of one of the VK variants. Bad gut health=bad VA, VK.
My how things get complex!!
So, what’s the take-home on all this?
Is VA a problem with VD? Well, it depends. I’d buy the position Masterjohn puts forward that a balance is necessary for these nutrients, but the REALLY important point here is the balance becomes ever more important as the DOSAGES INCREASE. Consider this:
If we take in large amounts of these fat-soluble vitamins we are “committed” down this course of action. Right ratios, wrong ratios, this is where we are going. Did you balance you supplements correctly? Get the right amounts of VA,VD,VK? Are you SURE? Just asking.
By contrast however you cold get your VD as such:
Conversion of cholesterol to VD via UV light exposure. When your body has enough, it makes no more.
Your VA by:
Conversion of carotenoids to VA and again, when you body ahs enough, production halts.
Absorption from plants, fermentation from gut bacterial. Both are dependant on a healthy gut.
Now, I may be completely wrong here. Perhaps the superior way to get all this is via cod liver oil, but here is my seriously wacky position:
If you eat the bulk of your protein from grass fed/wild caught sources, eat seasonal veggies and fruits, get some sun on your skin, keep your gut healthy (no grains and legumes, limited diary) you do not NEED any supplements. If you have not noticed I tend to be very reticent to suggest much beyond fish oil, magnesium and a few odds and ends. There ARE studies suggesting large dose antioxidants and supplements are NOT good for you, so I’m trying to make the best recommendations I can while also maintaining some kind of integrity in all this. I could make a pretty good bit of money hawking supplements but I’m hard pressed to find need for them other than in specific situations.
After 4 days of reading studies, looking at metabolic pathways and trying to make sense of stuff I honestly am not that jazzed about, I don’t know that it really matters one way or the other. If your ducks are in a row I doubt cod liver oil (vitamin A) is going to be a problem, but then again, I’m hard pressed to find a legitimate argument FOR it. Until I see convincing evidence to change this I’m going to keep recommending a minimalist approach: Grass fed meats, loads of seasonal fruits and veggies and call it good. Y’all can do what you want! The whole thing honestly boils down to this for me: