The authors regret that the ratio of milk protein to vitamin D was given incorrectly in the original article. Consequently, the sentences in the paragraph on vitamin D solutions in the left column on page 4954 should be adjusted as follows. The sentences beginning “In 50 mL centrifuge tubes…” should be correctly given as “In 50 mL centrifuge tubes, whey and caseinate complexes were prepared by dissolving Lacprodan DI-922A and MIPRODAN 30 Sodium Caseinate (Arla Foods Ingredients, Viby J, Denmark), respectively, in 55 mg mL-1 glucose solution. Crystalline vitamin D3 (DSM Nutritional Products, Basel, Switzerland) was dissolved in 99.8% ethanol (Honeywell, North Carolina, USA) (0.6 mg mL-1) and added to the centrifuge tubes in the ratio 4.6 : 1 (milk protein : vitamin D) and shaken vigorously, creating a final vitamin D3 concentration of 30 µg mL-1.” Throughout the paper, it should be referred to a protein: vitamin ration of 4.6 : 1 instead of 2 : 1 but the error has no impact on the results or conclusions of the work. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.