In addition to low systemic levels of circulating mineral ions (for example, caused by vitamin D deficiency or renal phosphate wasting) that result in decreased bone and tooth mineralization, accumulation of mineralization-inhibiting proteins and peptides (such as osteopontin and ASARM peptides), and small inhibitory molecules (such as pyrophosphate), can occur in the extracellular matrix of bones and teeth, contributing locally to cause matrix hypomineralization (osteomalacia/odontomalacia).

[8][9] The Stenciling Principle for mineralization is particularly relevant to the osteomalacia and odontomalacia observed in hypophosphatasia (HPP) and X-linked hypophosphatemia (XLH).

[11] Less common causes of osteomalacia can include hereditary deficiencies of vitamin D or phosphate (which would typically be identified in childhood) or malignancy.

[11] Nursing home residents and the housebound are at particular risk for vitamin D deficiency, as these populations typically receive little sun exposure.

[citation needed] Osteomalacia in adults starts insidiously as aches and pains in the lumbar (lower back) region and thighs before spreading to the arms and ribs.

However, these physical signs may derive from a previous osteomalacial state, since bones do not regain their original shape after they become deformed.

Osteomalacia due to malabsorption may require treatment by injection or daily oral dosing[20] of significant amounts of vitamin D3.