The Temporal Change in Ionised Calcium, Parathyroid Hormone and Bone Metabolism Following Ingestion of a Plant-Sourced Marine Mineral + Protein Isolate in Healthy Young Adults

<b>Background:</b> An increase in plant-sourced (PS) nutrient intake is promoted in support of a sustainable diet. PS dietary minerals and proteins have bioactive properties that can affect bone health and the risk of fracture. <b>Methods:</b> In a group randomised, cross-over design, this study evaluated the post-ingestion temporal pattern of change in arterialised ionised calcium (iCa), parathyroid hormone (PTH), <i>C</i>-terminal crosslinked telopeptide of type I collagen (CTX) and procollagen type 1 amino-terminal propeptide (P1NP) for 4 h following ingestion of a novel supplement (SUPP) containing a PS marine multi-mineral + PS protein isolate. A diurnally matched intake of mineral water was used as a control (CON). <b>Results:</b> Compared to baseline, the change in iCa concentration was 0.022 (95% CI, 0.006 to 0.038, <i>p</i> = 0.011) mmol/l greater in SUPP than CON, resulting in a -4.214 (95% CI, -8.244 to -0.183, <i>p</i> = 0.042) pg/mL mean reduction in PTH, a -0.64 (95% CI, -0.199 to -0.008, <i>p</i> = 0.029) ng/mL decrease in the biomarker of bone resorption, CTX, and no change in the biomarker of bone formation, P1NP. <b>Conclusions:</b> When used as a dietary supplement, or incorporated into a food matrix, the promotion of PS marine multi-mineral and PS protein isolates may contribute to a more sustainable diet and overall bone health.