Multivitamins do not have a significant impact on Lipitor's efficacy in lowering cholesterol levels. Lipitor, a medication used to treat high cholesterol, works by inhibiting the HMG-CoA reductase enzyme, which plays a crucial role in cholesterol production in the body [1].

Multivitamins, on the other hand, are supplements that contain various vitamins and minerals, and they are typically used to provide nutritional support [2]. They do not interact directly with the HMG-CoA reductase enzyme or have any significant effect on cholesterol metabolism [3].

It is important to note that certain medications, such as grapefruit juice, can interact with Lipitor and affect its efficacy [1]. However, multivitamins do not have any known interactions with Lipitor that would impact its ability to lower cholesterol levels [3].

In conclusion, multivitamins do not affect Lipitor's efficacy in treating high cholesterol. As with any medication, it is always important to consult with a healthcare provider before starting any new supplements or medications.

Sources:
[1] "Lipitor (atorvastatin)". Drugs.com. <https://www.drugs.com/lipitor.html>.
[2] "Multivitamin/multimineral". MedlinePlus. <https://medlineplus.gov/druginfo/meds/a607033.html>.
[3] "Drug Interactions: Atorvastatin (in Lipitor)". DrugPatentWatch.com. <https://www.drugpatentwatch.com/drugs/atorvastatin/interactions>.