I had to raise my hemoglobin levels from 12.8 to 15.6 in four days. I did it with iron pills (60 mg a pill, I think). I took two pills daily, with orange juice, as this maximizes absorption. In that short a time frame, absorption is critical. Here's other info I've saved about hemoglobin (basically, it's a choice between the iron pills or changing you diet to incorporate more of the below foods):
The iron in your body is called "elemental iron". Oral iron supplements contain different amounts of elemental iron. When you choose a supplement, be sure to check the label to see how much elemental iron it contains; a greater amount means that more iron will be absorbed by your body.
Typically, adults need to get between 60 and 120 mg of iron a day. The best way to take the supplement so that you absorb the greatest amount of iron is to take it in two or more doses during the day.
Although the supplements work best on an empty stomach, you may want to take them with food so that they don't upset your stomach.
You shouldn't take iron supplements with milk, caffeine, antacids or calcium supplements. These can decrease the amount of iron that is absorbed.
Take your iron supplement with vitamin C (for example, a glass of orange juice) one hour before eating, to increase absorption. Don't be alarmed if your stool gets very dark; it's from the iron.
Recommended foods to boost iron:
Spinach
Oysters
Kidney beans
Beef liver
Tofu
Beef (chuck roast, lean ground beef)
Whole wheat bread
Tuna
Eggs
Shrimp
Peanut butter, peanuts
Leg of lamb
Brown rice
Raisin bran (whole grain-enriched cereals)
Blackstrap molasses
Lentils
Beans (green, kidney)
Artichokes
Nuts
Peas (black-eyed peas)
Avocado