Milk Basic Protein (MBP) is a fraction of proteins derived from whey, found in small amounts in bovine milk. Its use to support the skeletal system, particularly bone health, is primarily justified by scientific evidence, though the body of evidence is moderate rather than robust. MBP contains several bioactive proteins such as lactoferrin, lactoperoxidase, and others, which have been shown in laboratory and some clinical studies to influence bone metabolism. Specifically, MBP is reported to stimulate osteoblast (bone-forming cell) activity and inhibit osteoclast (bone-resorbing cell) activity, theoretically promoting bone formation and slowing bone loss.

Several small-scale human clinical trials, mostly conducted in Japan, have shown that MBP supplementation (typically around 40 mg daily) can reduce markers of bone resorption and, in some cases, modestly increase bone mineral density in postmenopausal women and other populations at risk of osteoporosis. However, these studies are generally limited in sample size and duration. There is a lack of large-scale randomized controlled trials or replication in diverse populations, which limits the strength of the evidence.

In summary, while MBP is not a traditional remedy, current scientific research suggests it may support bone health by modulating bone metabolism. The evidence is promising but not definitive, warranting a moderate evidence rating.