Cave Man Mind has already admirably covered why taking supplements to replace is both desirable and paleo, rather than taking supplements to supplement i.e. to add more of a good thing (nutrient) because more is arbitrarily assumed to be better. In a lot of cases supplemented nutrients are disanalogous to nutrients from food (e.g. vitamin C being inefficiently absorbed if not accompanied by bioflavanoids).

I think there's another interesting question though, which is whether you can produce optimal benefits beyond those that are paleo. Kurt at Panu seems to argue that you can't, but I think it's clear that you can, with extra-large doses of niacin being the best example. If the optimal amount of meat and protein for you is X, (and it gives you Y niacin), but the optimal amount of niacin for you is 2Y, then plausibly it's better to supplement than to double your protein intake.

Another interesting, though controversial, example of possibly doing better-than-paleo would be omega 3-6 balance. Perhaps throughout almost all of our evolutionary history we never went much higher than a 1:1 ratio, after all we wanted a robust inflammatory response. Far more important to be able to rapidly fight off infection and heal wounds, than to reduce chronic inflammatory disease. In our current environment, I wouldn't be surprised if we do better encouraging less inflammation (perhaps giving us longer colds), but reducing the harms of a myriad stressors.

If only I could live a true paleoish life- wandering around the woods, sunning myself in the clearing...but alas, I am a web developer, so I spend large amounts of my time indoors under artificial light sitting at a desk. I'm starting to realize that as long as I live like this, I'm not going to get all the benefits of the paleo paradigm, but switching careers takes a long time. So I take vitamin D and wait for my ultimate escape into the wild.

People who have a modern aversion to offal that they can't conquer or who just don't have time to add it to their diets might also need supplements. Bones in particular have a lot of nutrients you just can't get elsewhere. It's even theorized that eating them was what provided the nutrients to support big brains.

Robb Wolf discussed supplements in the 15th of the Paleolithic Solution podcast. http://robbwolf.com/2010/02/16/the-paleolithic-solution-episode-15/

He shared the sentiment that vitamin D was essentially replacing the lack of outside activity and such.

I'm with you gilliebean, I've been wondering myself that lately. Especially since there has been a meta-analysis done on vitamins recently, showing that some of them actually are dangerous to take.

I stopped taking my multi, because I found it made me feel gross & headachy. I probably should go back to taking Vit D, especially since I live in the Pacific NW. But I wonder if maybe I shouldn't just focus on getting outside more (to which, I make sure to take a 30 min walk outdoors during the day). Because maybe those pills aren't so magical...

"In a meta-analysis study published in the Journal of the American Medical Association, researchers reviewed 68 studies involving more than 200,000 patients to determine whether taking high-dose vitamin supplements -- in particular, beta carotene, vitamin A, vitamin C, vitamin E and selenium -- affected your risk of dying.

What they found was that some of these supplements actually increased risk of death by a small, but significant, amount.

Taking large doses of vitamin A increased the risk of death by 16 percent. Smaller increases were seen for vitamin E (4 percent) and beta carotene (7 percent).

Vitamin C and selenium did not appear to affect the risk of dying."

-ABC News Are Too Many Vitamins Bad for Your Health?

http://abcnews.go.com/Health/Diet/story?id=2908054&page=1

And then there's also...

Vitamin E won't help, may hurt, cancer study says (Seattle Times)

http://seattletimes.nwsource.com/html/health/2004250179_vitamincancer29m.html

The Only Reasonable Paleo Principle covers this in a way, supplements are for when you aren't getting enough from your diet, e.g. its impossible to get the same amounts as our bodies are adapted for from diet alone in some cases.

The other half is the "isn't x not paleo?" argument which can make many lose focus of the point.

A better question to ask is "Is x healthy for me?" Which can be answered by the following: does my body expect it? and benefit from it? And in what amounts?

Absolutely correct. If you eat 100% natural and get lots of sunlight then you probably don't need supplements. People who do use supplements are usually deficient or simply want to ensure they are processing enough of a certain mineral or vitamin. My guess is people who supplement K and D work indoors and don't see the sun often or have stopped drinking milk and are afraid they won't get enough D.

I'm a tool-using human who likes to investigate and tinker with the world, including myself...

Are supplements like food? I'd say no. Are they a food replacement? No, again.

I think they are more like fine tuning and dialing-in the last of the micro-nutrients that may be rare and thus hard to hunt and gather. Or, in addition they are more like OTC medicines in the minor-use sense.

This might be a little off, but my current sense about my own body is that I am trying to counteract 20+ years of SAD living, and since I'd like a full recovery in less than 20 years, a few choice supplements like Krill Oil and Iodine will help me along.

I'm not a reenactment type, I think that a deep understanding of my biological systems that evolution has equipped me with will let me pick well.

PaNu points out that "Tolerated is not Optimal"... I'm just on the hunt for all the optimal I can find!!!

So yes, grass-fed meat is good for me, but anything else that my body can use to run as close to optimally is also (Natch) Good For Me.

As far as Vitamin A and E affecting early demise, they should be balanced. Frim what I've read, as long as the extra A & E are balanced with D and K, in other words all of the fat soluble vitamins are balanced to correct proportions, the toxicity can be at least minimized if not eliminated. That's part of the reason so many people on SAD have vit A problems, they don't get enough sun and therefore enough d.

In a perfectly Paleo world, supplements are not necessary. But we don't live on a pristine planet with access to pure clean food and water. We live on Earth in 2010, and our environment is full of toxins. In addition, many of us have eaten very bad food for many years. These two factors can trash the immune system.

Well-made, carefully chosen supplements can definitely strengthen your immune system. I recommend whole food supplements whenever possible. I'm a big fan of the New Chapter brand, because their supplements, while expensive, have helped me. Their only problem is that they use some soy in their supplements. Granted, most of the soy they use is fermented, but it is still soy. Their Zyflamend supplement is great for people who are new to Paleo eating. If you've eaten Paleo for many years, and have taken steps to reduce the toxins in your environment, then you will find you need less supplementation, and at some point even none. It's an individual choice.