I'm not gonna translate since I used Machine Translation, but according to DeepL the artist commentary is about eletrical thighs
電 : Inazuma (in this case, a proper noun) 太もも : thighs linked by の : Inazuma's thighs
得 : to get, to acquire, to obtain ; conjugated here with the potential られ and the negative ない, meaning "cannot be acquired" In this context, the prefix しか is most literally translated as "excepted" meaning "cannot be acquired excepted for..." ; in English this kind of thing is more commonly expressed using the affirmative with "only" i.e. "can only be acquired..." I'm not entirely sure how the からで in the middle works but I think it basically just links the preceding noun and following verb and could be simply translated as "from" thus so far 電の太ももからでしか得られない : "Can only be acquired from Inazuma's thighs"
My dictionary says 栄養素 means nurtients and who am I to question The Almighty Dictionary of the Many Kanjis I Don't Know(tm) (the kanji for honour, one that means taking care of/raising, and the kanji for prime numbers... put together, means nutrition. I love Kanjis) が this is a subject marker ある this is "to exist" and is more aptly translated by "there is/are"
So in total, if I didn't get anything wrong : "There are nutrients that can only be acquired from Inazuma's thighs." That's the best I can do.
