Were your levels always low, Adam? Some people have lower levels than others, by default. No matter what they do or eat. And what are they comparing your levels to, to the male or the female standard? Women have lower levels, so, that could be a factor to why yours is on the low side, but, you not having real problems with it.
Drink your coffee, thee and milk products between meals. Not with meals. And have vitamin C with every meal you take. Vitamin C helps you to absorb iron.