I have had dogs in the past but I haven't in years. And since then a new catergory of food has arrived. What is "Large Breed puppy food/Adult dog food" suppose to do different then what we used in the past.
large breed dog food is formulated to have less protein so that the dogs don't 'grow too fast'. The faster a large breed dog grows, the more strain it will put in growing bones and joints, and it increases the likelihood of causing later health problems.
I'd never give my dog or advise anyone give their dog a straight calcium supplement personally, because giving just calcium can cause the phosphorous and magnesium balance to get out of whack as they are all very closely linked. A broad-spectrum supplement like "Missing Link" would be better advised.
Keith, our local Wild Oats (organic, natural food store) carries missing link. You wont' find it at petco (at least not mine) but the specialty shops usually carry it. Funny thing is that Missing Link is for human and dog. So enjoy.