Background: Calcium is essential for bone health, but its intake remains inadequate in populations with limited dairy consumption. Fish bones, abundant in calcium and phosphorus, represent a largely untapped natural resource for dietary calcium supplementation. The application of high-energy ball milling (HEM) presents a promising strategy to enhance calcium bioavailability by producing particles at the nanoscale. Methods: This study used HEM to convert fish bones from Euthynnus affinis (tuna) and Lutjanus sp. (snapper) into nanoparticles. The resulting powder was analyzed for particle size, morphology, crystallinity, thermal, flowability, hygroscopicity, mineral composition, and proximate constituents. Results: The HEM process successfully reduced the particle size of snapper and tuna bone powder to 729.83 and 847.93 nm, respectively, without altering their crystallinity. Morphological analysis revealed irregularly shaped particles, while thermal analysis indicated an exothermic decomposition pattern. No hygroscopic properties were observed in any of the samples. The nanonization process preserved the intrinsic mineral composition of the fish bones. Calcium/Phosphorus ratios remained >1.8. Elemental analysis confirmed high levels of calcium, phosphorus, and essential minerals such as potassium, magnesium, and sodium, while the protein and ash contents met nutritional standards. Conclusions Fish bone-derived nanoparticles produced via HEM exhibit advantageous physicochemical characteristics for nutraceutical applications and represent a promising source of bioavailable calcium to support bone health.

Objectives: This study investigated factors associated with the retention of people living with human immunodeficiency virus (HIV) on antiretroviral therapy (ART) during the first 3 years of treatment. Methods: A retrospective study using electronic health records was conducted at a tertiary hospital in Jakarta, Indonesia. Adult HIV-positive patients who started ART from 2010 until 2020 were included. A binary logistic regression model was used to identify factors associated with ART retention in the first 3 years. Results: In total, 535 respondents were included in the analysis. The ART retention rates for the first, second, and third years were 83.7%, 79.1%, and 77.2%, respectively. The multivariate analysis revealed a negative association between CD4 count when starting ART and retention. Patients with CD4 counts >200 cells/mL were 0.65 times less likely to have good retention than those with CD4 counts ≤200 cells/mL. The year of starting ART was also significantly associated with retention. Patients who started ART in 2010-2013 or 2014-2016 were less likely to have good retention than those who started ART in 2017-2020, with adjusted odds ratios of 0.52 and 0.40, respectively. Patients who received efavirenz-based therapy were 1.69 times more likely to have good retention than those who received nevirapine (95% confidence interval, 1.05 to 2.72). Conclusions Our study revealed a decline in ART retention in the third year. The CD4 count, year of enrollment, and an efavirenz-based regimen were significantly associated with retention. Patient engagement has long been a priority in HIV programs, with interventions being implemented to address this issue.