Fish, including fish bones and shell-derived ingredients (such as oyster shell or fish bone powder), have garnered scientific interest for their potential to support osteoporosis prevention and treatment. The primary rationale centers on their high content of bioavailable calcium, phosphorus, and, in some cases, vitamin D, all of which are essential for bone health. Several studies have demonstrated that calcium derived from fish bones or shells is well absorbed and effective in improving bone mineral density in both animal models and limited human trials. For example, calcium from fish bone powder has shown comparable absorption to standard calcium carbonate supplements in clinical assessments. Additionally, fish are a source of omega-3 fatty acids, which may have ancillary benefits for bone turnover and inflammation reduction, although this effect is less direct than calcium supplementation.

While the majority of clinical research focuses on isolated fish bone or shell-derived calcium rather than whole fish, traditional diets rich in small, bone-in fish (such as sardines) have been epidemiologically associated with better bone health outcomes. Regulatory authorities recognize calcium supplements from marine sources as effective, provided contaminants are controlled. However, large-scale, long-term randomized controlled trials in humans are limited, so while there is scientific plausibility and supportive evidence, it is not yet at the level of robust clinical guidelines.