Romijn sports a 'milk moustache' on her upper lip while holding little Dolly and Charlie for the pictorial.
The ad is part of Got Milk's Great Gallon Give campaign, which emphasises the importance milk plays in building strong families.
The actress says, "I know that milk is a valuable part of building a stronger family. For me, milk is the best choice. It supplies so many nutrients that are important for my children's development - and to my overall health, too. I encourage all moms to make it easier to build a strong family in 2010 by setting their table with milk."
Romijn and husband Jerry O'Connell welcomed the twins on 28 December 2008.