Nutritional diseases remain a common presentation for captive reptiles. To date, much of the research has focused on mineral contents of diets, with less focus on broader topics such as how much protein, fat, moisture, trace elements, and vitamins are needed. Measuring the digestibility of a diet is one method of gaining insight into how reptiles process the nutrition they are offered. In this experimental study, 10 northern blue tongued skinks (Tiliqua scincoides intermedia) were offered three diets (Group 1: cat food, Group 2: high calcium dubia roaches, Group 3: low calcium dubia roaches) in a complete crossover study to determine the digestibility of the diets. Appropriate washout periods were provided between trials based on pilot studies investigating gastrointestinal transit times. Because of the quantity of feces needed for sampling (15 grams), the feces from the skinks were pooled for analysis. Samples were collected daily and frozen at -80oC until being analyzed at Dairy One (Ithaca, NY, USA). The authors’ hypothesis was that a higher proportion of a nutrient would be absorbed from a diet with a lower concentration of the nutrient compared to a diet with a higher concentration of the nutrient. As an example, this hypothesis was true for calcium, where absorption of calcium was significantly higher (P < 0.02) in groups 1 and 3 compared with group 2. These results affirm the need to evaluate how reptiles process their diets and that “more of something” (e.g., calcium supplementation) isn’t necessarily “better”.