This condition is brought on by a lack of vitamin D, which causes the body to be unable to absorb or deposit calcium. Less commonly, it can also be caused by a lack of calcium or phosphorus, but vitamin D deficiency is by far the most common cause.
8 ways to avoid paying an airline change fee. Everyone's been there: having to change a flight and facing a fee that's almost as much as the original airfare. (Change fees can be $200 on airlines like American, United and Delta, and international flight changes can cost up to $450). Most of us have resigned ourselves to paying the fee of changing our itinerary, no matter how far out the trip still is, but you shouldn't have to.
American charges a $200 change or cancel fee for paid domestic flights (itâs as high as $450 for international travel). That fee is charged per flight! If you change or cancel a domestic round-trip flight, you will pay $200. If you change or cancel two one-way domestic flights you will pay $200 for each - or $400! Call American if you have an extraordinary circumstance like illness, a death in the family or a natural disaster.