I think I have some links in the stickies here.

These are my favorites:

Linus Pauling Institute at Oregon Univ.
http://lpi.oregonstate.edu/

Government one is not too "bad"
http://ods.od.nih.gov/Health_Informa...pplements.aspx

University of Maryland:

http://www.umm.edu/altmed/
This one is especially good because it gives MORE interactions with DRUGS....

iherb has very good links too: (also is a good source with high quality and low prices, low shipping, and fast service)
http://healthlibrary.epnet.com/GetCo...chunkiid=33802

And you can always ask here, and I can help you too, along with others here who have
had alot of experience in this area.

I am not back yet, but will be back daily sometime after the middle of next week.

I can't address your questions fully now...I don't have my regular computer.
But I do NOT recommend high dose Vit C to older patients, without medical supervision.
Doses over 250mg have been implicated in harming diabetics. High doses also acidify the urine
and may negatively impact other drugs elimination from the body.
I am not familiar with opiates being stored in fat cells. THC from marijuana is stored in fat cells for long periods of time (up to months).
When I get back I will look that up for you.....but you can double check that by checking
sites with drug urine testing information. But I suspect the amounts released if stored would not
be high in concentration or therapeutic.

Typical Cal/Mag tablets do NOT have good form of magnesium for you. Check your labels...if Magnesium OXIDE you are not getting much of anything from them. I have a magnesium thread here that discusses what are the better types.

I need to know what drugs you are taking in order to look them up for you specifically and how they impact nutrients in your case. That reference is at home. You can send them to me via PM if you prefer for confidentiality. What you are doing now is "hit or miss"...so we need to clear that up for you. I also need to know if you have normal kidney functions and what your serum creatinine is.
The higher the number the more careful you need to be about vitamins/minerals.
It is not good to take several multi types...you may be getting too much iron for a man.

So please send me that list.