Background: A chronic low-grade inflammatory profile (CLIP) is associated with sarcopenia in older adults. Protein and Vitamin (Vit)D have immune-modulatory potential, but evidence for effects of nutritional supplementation on CLIP is limited. Aim: To investigate whether 13 weeks of nutritional supplementation of VitD and leucine-enriched whey protein affected CLIP in subjects enrolled in the PROVIDE-study, as a secondary analysis. Methods: Sarcopenic adults (low skeletal muscle mass) aged ≥ 65 years with mobility limitations (Short Physical Performance Battery 4–9) and a body mass index of 20–30 kg/m 2 were randomly allocated to two daily servings of active (n = 137, including 20 g of whey protein, 3 g of leucine and 800 IU VitD) or isocaloric control product (n = 151) for a double-blind period of 13 weeks. At baseline and after 13 weeks, circulating interleukin (IL)-8, IL-1 receptor antagonist (RA), soluble tumor-necrosis-factor receptor (sTNFR)1, IL-6, high-sensitivity C-reactive protein, pre-albumin and 25-hydroxyvitamin(OH)D were measured. Data-analysis included repeated measures analysis of covariance (corrected for dietary VitD intake) and linear regression. Results: IL-6 and IL-1Ra serum levels showed overall increases after 13 weeks (p = 0.006 and p < 0.001, respectively). For IL-6 a significant time × treatment interaction (p = 0.046) was observed, with no significant change over time in the active group (p = 0.155) compared to control (significant increase p = 0.012). IL-8 showed an overall significant decrease (p = 0.03). The change in pre-albumin was a significant predictor for changes in IL-6 after 13 weeks. Conclusions: We conclude that 13 weeks of nutritional supplementation with VitD and leucine-enriched whey protein may attenuate the progression of CLIP in older sarcopenic persons with mobility limitations.