Methods of treating MDS, or ameliorating a symptom thereof, are disclosed. Specific methods encompass the administration of one or more vitamin D compounds, or a pharmaceutically acceptable salt, solvate, hydrate, stereoisomer, clathrate, or prodrug thereof, alone or in combination with one or more additional active agents. Other methods include intermittent administration of a high dose of one or more vitamin D compounds, or a pharmaceutically acceptable salt, solvate, hydrate, stereoisomer, clathrate, or prodrug thereof, alone or in combination with one or more additional active agents. Such intermittent administration allows high doses of the vitamin D compounds to be administered while minimizing or eliminating hypercalcemia.