Yeah, it supports 5V or 3V3 for power, but the signal lines are not 5V tolerant ... there's nothing on there that corrects that. You need a level converter on all the signal lines. Something like a TXB0104 (or TXB0108). Earlier I suggested this level converter as well, however after more testing I found out it's really slow and hinders fast SPI communications. In order for that to work on an SD card, I had to slow down the SPI data transfer rate considerably. I've since switched to an TXB0108 and can now run SPI at full speed reading/writing to an SD card.