"When we're like...we both have nothing to wear LOL @emrata," Kardashian wrote, referencing her original caption.
"We are more than just our bodies, but that doesn't mean we have to be shamed for them or our sexuality. #liberated @kimkardashian," Ratajkowski added.
The "Blurred Lines" video star was one of several celebrities to show their support for Kardashian's controversial selfie, posting a nude photo of her own after the scandal. She herself faced criticism from social media users who suggested she's too thin.
Kardashian defended her selfie as an expression of confidence and sexuality in a blog post on her website this month. The reality star responded to those who criticized her for going nude as a mom of two by saying she's "allowed" to be sexy as a mother.
"I am empowered by my body," the star wrote. "I am empowered by my sexuality. I am empowered by feeling comfortable in my skin. I am empowered by showing the world my flaws and not being afraid of what anyone is going to say about it."
"It's 2016. The body-shaming and slut-shaming -- it's like, enough is enough," she added. "I will not live my life dictated by the issues you have with my sexuality. You be you and let me be me."
Modern Family star Ariel Winter and model Amber Rose are among the other stars who voiced their support for Kardashian. The reality star and her family will return on E! series Keeping Up with the Kardashians in May.