Vitamin D deficiency is acknowledged as a general health concern globally, particularly among populations with limited sunlight exposure. Beyond its well-known role in musculoskeletal health, vitamin D holds a myriad of under-recognized health benefits, from cardiovascular health, immunity, brain function, to fertility and other chronic diseases. Primary care physicians play a key role in preventive health strategies, including counseling and supplementation practices. Understanding patient behaviors and beliefs is essential for improving preventive care and reducing deficiency-related complications.To determine the prevalence and predictors of vitamin D supplementation among adult patients attending a family medicine practice, to evaluate the supplementation behaviors and to identify opportunities for improving preventive counseling on vitamin D in family medicine.A cross-sectional survey was conducted between November 2025 and December 2025 in a family medicine practice in Bucharest. A total of 100 consecutive adult patients attending routine consultations were invited to complete a structured questionnaire with 10 questions on vitamin D intake, sources of information and perceived benefits. Data on age, gender and comorbidities were collected from medical records. The inclusion criteria were: patients aged 18 years old and above, attending a non-emergency appointment, able to read and complete a short form. Descriptive and inferential statistical analyses will be performed to explore associations between supplementation and demographic factors. Data analysis is ongoing.(Anticipated results): Although data collection is ongoing, early patterns suggest suboptimal adherence to vitamin D supplementation during winter. The final results are anticipated to clarify which patient groups are least likely to supplement and to highlight opportunities for improving counseling and prevention in the family medicine setting. Comprehensive findings will be presented at the conference.Initial observations indicate suboptimal supplementation practices among adult patients. This highlights a broader public health challenge in regions with limited sunlight exposure. Understanding patient motivations and barriers may support the development of community-level prevention strategies grounded in primary care insights.Early findings suggest that vitamin D supplementation remains inconsistent among adults. Preliminary trends emphasize the importance of patient education regarding vitamin D and its health benefits. Strenghtened communication and counseling in family medicine could improve supplementation practices.