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.
If you bought a refundable ticket, then you should be able to get all your money back with little or no fees but for non-refundable tickets the following fees apply: 1  American Airlines does not refund your ticket price except when the passenger dies or when cancellation is due to military orders. To change your ticket is typically $200 for domestic tickets. Delta Airlines does not offer refunds and charges a $200 change fee for domestic flights.