Vitamins & Minerals:
Think of vitamin sources and most people come up with vegetables and fruits. However, most vegetables contain more water than anything and only about 30% to 50% of those eaten by people are easily digested by dogs. And, vegetables are ridiculously low in fat to be of any value as an energy source. Fruits are a great source of vitamin C — and dogs really don’t need it.
Actually minerals are most critical for canine health, especially calcium and phosphorus. Dogs often require some supplement of these in part because commercial food ingredients (meat, meat byproducts,
soybeans, casein and eggs) contain low levels of both, in the wrong ratio. Milk and bone meal 
are excellent sources to supply calcium and phosphorus, as well as magnesium, in easily digested form.
