The latest studies suggest a possible influence of homocysteine (Hcy), folate, vitamin B6, and vitamin B12 on bone metabolism, bone quality, and fracture risk. Osteoporotic fractures represent a significant public health issue and are associated with morbidity and mortality. It is believed that lifestyle factors also affect Hcy levels in a healthy population. Some epidemiological studies indicate a slight increase in Hcy levels in individuals with poor dietary habits (low folate intake), smokers, and coffee drinkers, as well as vegetarians (low vitamin B12 intake). However, data on individuals who consume alcohol and those who are physically active are inconsistent. Moreover, the role of Hcy in bone metabolism is currently poorly understood, and it remains unclear whether improved folate and vitamin B12 status or simply reducing Hcy levels prevents bone fragility. Research Objectives: To determine Hcy levels in populations at risk due to the intake of these micronutrients and the prevalence of osteoporosis. To assess bone quality in individuals with slightly elevated Hcy levels and evaluate whether adequate intake of folate and/or vitamin B12 (through diet and/or supplementation) positively impacts bone tissue quality. To investigate whether participants adopt new dietary behaviors during the follow-up period (study duration) and the resulting impact on Hcy levels and bone quality. Expected Results: A slightly elevated Hcy level is expected in a significant number of participants. After a one-year intervention, premenopausal and postmenopausal women (aged 45–65), older adults (>65 years), vegetarians (aged 30–50), and individuals with celiac disease (aged 18–60) are expected to achieve adequate folate and/or vitamin B12 status, lower Hcy levels, and improved biomarkers of bone formation and resorption, as well as bone density. During the follow-up study, a considerable number of participants are anticipated to adopt new dietary behaviors. Methods for Result Verification: Random allocation of participants into groups. Use of placebo. Double-blind study design. Significance of the Proposed Research: International Level: This study would contribute to the currently unresolved understanding of the role of folate, vitamin B12, and Hcy in bone quality. National Level: It would provide data on the status of folate, vitamin B12, and Hcy levels in at-risk populations and their correlation with bone mineral density.