Based on the available information, there is no definitive evidence to suggest that consuming dairy products decreases the effectiveness of Lipitor (atorvastatin), a medication used to treat high cholesterol levels.

According to the PubMed study [${2}], there was no significant interaction found between atorvastatin and dairy products. The study investigated the effect of consuming dairy products on the bioavailability of atorvastatin in healthy volunteers and concluded that dairy intake did not significantly impact the drug's absorption or effectiveness.

However, it is important to note that individual responses to medications can vary, and other factors, such as age, genetics, and the presence of other medical conditions, can influence the effectiveness of Lipitor. The UptoDate article [${3}] on high cholesterol and lipid treatment options beyond the basics does not mention any interaction between Lipitor and dairy products.

In summary, based on the available information, there is no evidence to suggest that consuming dairy products decreases the effectiveness of Lipitor. However, individuals should always consult with their healthcare provider before making any changes to their medication or diet regimens.

Sources:

* <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
* <https://pubmed.ncbi.nlm.nih.gov/21371558/>
* <https://www.uptodate.com/contents/high-cholesterol-and-lipid-treatment-options-beyond-the-basics/print>