What Effect Does Vegetarianism Have on the Mineral Density of Bones?

Background: Low calcium intake in vegetarians can negatively impact bone health, with factors like oxalate, phytate, and fiber reducing calcium bioavailability. However, long-term effects on calcium retention and density are not proven. Calcium intake is crucial for bone health and preventing osteoporosis. Aims: This research aims to investigate the impact of a vegetarian diet pattern on our studied Jordanian BMD while taking the impactful effects of calcium supplementation. Methods: A study examining 328 patients with suspected osteoporosis, osteopenia, or osteoporotic fractures at Prince Rashid bin Al-Hussein Military Hospital between August and October 2023, used data from the hospital's medical record system and dual energy X-ray absorptiometry database. The study categorized the vegetarian diet pattern into four groups based on frequency of adherence and the number of calcium supplements taken per week. The analysis of covariance (ANCOVA) was conducted to determine the means, standard errors, and confidence intervals for patients' bone mineral density (BMD) in each category of the investigated vegetarian diet patterns. A chi-square was conducted to abstract distribution rates and their level of significance. The study was approved by the Jordanian Royal Medical Services' Institutional Review Board (IRB) committee on July 11, 2024. Results: This study analyzed 328 patients, with 93 following an infrequent vegetarian diet pattern, 82 following an intermittent vegetarian diet pattern, 84 following a frequent vegetarian diet pattern, and 69 following an always vegetarian diet pattern. The age groups were divided into four categories: under 50, 50-59, 60-69, and 70 or older. The gender distribution was statistically significant, with 82.6% of patients being females and 17.4% males. Obesity statuses were classified based on body mass indexes, and the distribution of calcium supplementation patterns varied among the four groups. Functionality was also significantly distributed across the groups, while physical activity levels were insignificant. The femoral hip and lumbar bone mineral densities were statistically distributed across the four groups. The ANCOVA analysis revealed that patients' BMD had Means±SDs of 0.9174±0.16351 g/cm2, 0.9039±0.17476 g/cm2, 0.9098±0.13927 g/cm2, and 0.8791±0.13657 g/cm2 for the four vegetarian diet patterns. Conclusion: The study found that a vegetarian diet significantly impacts bone mineral density in Jordanian patients, potentially increasing their risk of osteoporotic fractures. This effect was more pronounced when the diet shifted to a vegan one, even after accounting for supplemental calcium. The study suggests conservative strategies when transitioning to a vegetarian diet, rather than relying solely on supplements.