Well, what I've understood from Dr. Cathcart and other places is that the ratio of AA to DHAA is a measure of the reduction/oxidation ratio in the body, which is a major determinator of health. High AA to DHAA ratio is a sign of health.

DHAA is simply the oxidized form of vitamin c, and although it is the form absorbed into cells, it must be reduced by glutathione to become active. Ester C, for example, is an inferiour product to ascorbic acid or mineral ascorbates because it contains DHAA and some breakdown metabolates.

Please correct any mistakes I may have made in the above.

Niacin and niacinamide are both referred to as B3 because both are able to cure pellagra. I would think that DHAA could cure scurvy, but since it breaks down so readily, it would be more challenging than AA. But I think we should be open minded and accept DHAA as a form of vitamin C.

The highest concentrations of vitamin C in the body are in the brain, but vitamin C cannot enter the brain itself. Only DHAA enters the brain, which is then converted by glutathione to AA. Part of the great benefit of IVC and high dose vitamin C is that as long as the serum C levels stay high, higher levels of DHAA will be constantly available for the brain tissue to take up to build its own vitamin C levels.

Actually this common saying was proved wrong.

Vitamin C can enter the brain via choroid plexus using SVCT2 transporters.

I fogilly remember there is some role DHA has on skin so it does make sense to put it there. I doubt there is much sense in adding DHA to the oral supplements because some of the oral AA will become DHA as soon as it enters harsh GI environment.