© 2021 The International Society for Clinical DensitometryBackground: Elderly people are considered to be in the risk group for vitamin D deficiency. The aim of the present study was to determine the effect of nursing interventions and sunlight exposure to reach optimum 25-hydroxyvitamin D [25(OH)D] levels by individuals living in nursing homes. Methodology: Randomized controlled experimental study was carried out in June-August 2018 period in the nursing home. The question form, standardized mini mental test, Fitzpatrick skin typing questionnaire and Katz Index of activities of daily living were applied. Individuals in the intervention group (n=20) was exposed to sunlight five days a week for four weeks in July with an average duration of 21 ± 5 minutes (min 15 - max 30 minutes). For the participants in the control group (n=20), sunbathing was not offered. 25(OH)D, calcium, parathormone, phosphorus, alkaline phosphatase and albumin levels of all individuals were measured at the beginning and end of the study. Results: At the end of the study, the 25(OH)D was significantly higher in the intervention group than in the control group (8.06 ng/ml and 0.96 ng/ml, respectively; p = 0.008). It was observed that in the intervention group, sunlight exposure increased the 25(OH)D regardless of gender and age. Increases were observed in intervention groups for calcium and albumin levels. At the beginning of the study, 25(OH)D was sufficient only in five elderly people in the intervention group, while at the end, 11 elderly people had sufficient levels of 25(OH)D. Conclusion: At the end of the study, it was concluded that sunlight exposure was a sufficient source to increase 25(OH)D in most elderly people living in the nursing home. Organizing sunbathing sessions as an independent nursing intervention is recommended for the elderly people living in nursing homes in order to prevent vitamin D deficiency and related consequences.