Yes. The ADEK's or Source CF are vitamins made especially for CF patients so that they are better absorbed. If you take OTC vitamins then it is advisable to take enzymes with them so that they will be absorbed easier. Without, then they are absorbed about the same as the vitamin found naturally in your food, which isn't much, being the reason CF'ers need supplements.
When my girls' dietician insisted that the ADEK's be chewed not swallowed, (my girls refused to chew them because they thought they tasted gross)we were told they could take OTC vitamins 2/day if they took enzymes with them. They did this for a number of years until we were told about Source CF vitamins. We order them over the phone directly from the manufacturer. When you order 3 or more bottles, shipping is free. Currently Anna' only takes One a Day Women's (or generic of that same type because it has more calcium) since she is post transplant and has to take enzymes with one of her anti-rejection meds to maintain her levels. She's not had any problems with her vitamin levels in 4 yrs. Rachel takes Source CF and only has issues with her Vit. D levels. We think due to Nebraska winters. Summer time when she returns home she has no issues. Same with Anna' pre-tx.