Choosing supplements -longish post

I'm feeding Leon cooked meat (chicken legs mostly), sometimes mixed with white rice and veggies. He has a sensitive stomach and doesn't eat much.

I want to supplement his diet with vitamins and calcium. I have bought from time to time several different products, but then had doubts about their quality.

Can anyone tell me what to look for and what to avoid in multivitamin and calcium supplements? How much of each nutrient should he be getting? I've googled but haven't been able to find recommended dosages for dogs as those that exist for humans.

Also, most formulas contain animal byproducts and/or cocoa. Are these unsafe even in the small amounts present in a tablet?

These are the multies I've bought:

VMP tablets by Pfizer
Pet-Form by Vet-A-Mix
Coco-Pet by Surepharm Services

And these are the calcium supplements:

Pet-Cal by Pfizer
VetStar by Veterin


I've also thought of giving him human grade calcium, like this one (http://65.200.170.239/cgi-bin/online_reference_new/online_ref.pl?function=Product&id=96756790113244), but it doesn't contain any phosphorus like the canine calcium supplements do.

I home cook as well

I feed fish, chicken, turkey, beef

Fish either fresh or canned: salmon/sardines/tuna/trout

With the fish the bones in sardines and salmon are HIGH in calcium so great source there!

I also give plenty of steamed veggies and rice or potato, even couscous and brown rice. I've never had any troubles and have a really happy dog.

Additionally I give her primrose and codliver oil but not daily 3 times a week (off days of the fish) and daily she gets yogurt for healthy bacteria and calcium.

I always add organic garlic powder to the food to keep away nasty biting insects like skeeters and fleas.

If ever any fleas I add some oregano oil to the yogurt and a little to the neck, chest and hind quarters. Never had a problem yet. :D

Raw beef bones to gnaw on for teeth cleaning :D bone marrow and calcium!

Yeah, I wish my dog would eat fish, steamed veggies, yogurt etc, but he doesn't. :(

He is only getting the vitamins/minerals that can be found in roast meat, which I'm afraid aren't enough to keep him in good health. That is the reason I'm asking the supplement questions.

the best source of calcium? tums, my dog was 70 pounds and I added 3 tums to her homemade food, I made a batch every two days. (Vet recommended). Its much cheaper than the calcium powder purchased at a nature store and more potent. The vet supplied me with multi vitamin tablets that was also dissolved into her meal. You can also add one scrambled egg to the mixture of rice.