What is the cause of low direct bilirubin?

Direct bilirubin low may be related to the recent diet, or intake of protein food is less, there are less blood-containing products to eat, so it will show a low bilirubin situation. But bilirubin low prompt liver function is normal, because bilirubin it mainly comes from aging red blood cells, and food inside, low is no problem, but if high, then you need to check and deal with.