There is no direct evidence or information from the provided sources that suggests an interaction between Lipitor (atorvastatin) and skim milk. Lipitor is a medication used to lower cholesterol and triglycerides in the blood. It is generally advised to take Lipitor with or without food, but it is essential to follow your healthcare provider's instructions regarding its administration. If you have concerns about potential interactions between Lipitor and specific foods, including skim milk, it is advisable to consult with your healthcare provider or pharmacist for personalized advice.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.webmd.com/drugs/2/drug-3330/lipitor-oral/details
[3] https://www.sciencedirect.com/science/article/pii/S2211383512000810