There are plenty of foods that have iron in them, and you can give the iron foods 30 minutes before or after milk for maximum absorption. I wouldn't bother with suppliments unless he abslotutely refuses every iron food you give him because iron in it's food form is so much better. Get creative. Pickles are a good source of iron, if he doesn't want to eat bits of pickle, you could puree a pickle and make a popcycle out of it that might sound crazy but we moms do what we have to do.
Next info taken from http://www.healthcastle.com/iron.shtml
Excellent sources of Iron
# Clams
# Pork Liver
# Oysters
# Chicken Liver
# Mussels
# Beef Liver
Good Sources of Iron
# Beef
# Shrimp
# Sardines
# Turkey
Excellent sources of Non-Heme Iron
# Enriched breakfast cereals
# Cooked beans and lentils
# Pumpkin seeds
# Blackstrap Molasses
Good sources of Non-Heme Iron
# Canned beans
# Baked potato with skin
# Enriched pasta
# Canned asparagus
Iron Absorption Enhancers
* Meat/fish/poultry
* Fruits: Orange, Orange Juice, cantaloupe, strawberries, grapefruit etc
* Vegetables: Broccoli, brussels sprouts, tomato, tomato juice, potato, green & red peppers
* White wine
Iron Absorption Inhibitors
* Red Wine, Coffee & Tea
* Vegetables: Spinach, chard, beet greens, rhubarb and sweet potato
* Whole grains and bran
* Soy products
One more little note I believe we give our kids Way too much milk. Most people think it's this super source of calcium. Well it does give some calcium but not nearly as much as people think because one of the ingredients in milk inhibits absorbtion of calcium. I don't remember wich ingredient it was but I read about it in Doctor Sears Book Nutrition for Families. So I would look for other Calcium foods as well. Hope this helps