The magnesium in mulitivits or combination products available in stores, is mostly magnesium oxide (not appreciably absorbed).

The magnesium stearate on the labels, is not absorbed. It is there as a powder lubricant for manufacturing purposes so the powder does not cake when moved thru the pressing machines.

The supplements we use on PN, are mostly not vitamins.
The Benfotiamine (thiamine) is B1 however. But the -r-lipoic is not.

Amazon has Doctor's Best products, and so does iherb.com
Swanson's has some of that brand too, at a discount. Local stores are not likely to have them, and if they do, full price would be double what the online places have.

D3 is available now in many stores. But the methylcobalamin is less likely to be available locally.

Do the R-lipoic stablized (must be this form) and Benfotiamine.
B12, a Centrum Senior formula (I use Costco's generic for this), magnesium from food. To start.
You should not need high doses of B6 other than the multivitamin.

example:
http://www.iherb.com/Doctor-s-Best-B...ie-Caps/4?at=0

http://www.iherb.com/Doctor-s-Best-B...e-Caps/42?at=0

One of each daily from the above.

Autoimmune damage, often becomes inflammatory, as cytokines move in when the antibodies do the damage.
Antioxidants scavage free radicals also to prevent more damage to the nerve tissue. I found that antioxidants completely removed my spider veins in my legs...when I was using them for the PN. So the antioxidants may improve your veins the same way. Some "vein" supplements contain various herbs like horsechestnut etc, but you can do the same for less $$ by using grapeseed extract. Alot of local stores have grapeseed extract, but Puritan's Pride has reasonable prices for this too.
Eating blueberries and strawberries and other foods of color, do the same thing.