Saadia is a very old name :
http://www.yucs.org/~jules/names/masc/saadiah.html
Saadia means "help of G-d", and Saad means "he [G-d] helps". Saadia is no female form of Saad.
The name Saada, "help", is female though.
Check:
http://www.hebrewletters.com/item.cfm?itemid=1379
http://www.hebrewletters.com/item.cfm?itemid=21552
~~ Claire ~~