Yes, it is too low. The Vitamin D Council exists so we can educate that those amounts are too low to keep a human body healthy. We recommend 5000 iu a day which should then allow you to reach a blood level of 50ng/ml (125nmol/l). If you weigh more than the average weight of 150lbs, then you may have to take more than the recommended amount in order to reach that blood level. The upper safe intake is 10,000 iu a day.
You also need to read http://www.vitamindcouncil.org/about-vitamin-d/vitamin-d-and-other-vitamins-and-minerals/. It is very important!