If you take anything from the recent controversy from a new report by the Institute of Medicine it is that they tripled the amount of vitamin D that they were recommending and doubled the amount that they considered a safe dose. The change in their recommendation was to increase what they were recommending from a week ago, before the report came out. The controversy is that it is less than what many other medical doctors are recommending (and prescribing), their concern for high doses of Vitamin D.
The report focused primarily on bone health and did not take into consideration the many other benefits of Vitamin D. Even with bone health, purchase the International Osteoporosis Society disagrees with their findings.
Last year I saw a significant decrease in colds and flu with my patients. I sincerely believe that it is because of an increased consumption of Vitamin D. I continue to make my recommendation of 5,000 iu for adults. 10,000 iu if you suspect you might be getting a cold or are around people that are sick, and up to 20,000 iu a day for up to one week if you get sick (The Vitamin D council states that chronic ingestion of 40,000 iu can lead to toxicity but will actually recommend 50,000 iu a day for seven days if you are sick.)