Osteomalacia
2 medicines
Osteomalacia is a softening of adult bone caused by severe vitamin D deficiency, leading to bone pain, muscle weakness and a higher fracture risk. It is treated by correcting vitamin D and calcium levels.
Key facts
- Osteomalacia is the softening of adult bones from impaired mineralisation, almost always driven by a severe, prolonged lack of vitamin D.
- Unlike osteoporosis, which thins bone that formed normally, osteomalacia affects the bone matrix itself, causing dull, deep bone pain, muscle weakness, and a tendency toward hairline fractures with minimal trauma.
- Treatment restores vitamin D status; active vitamin D analogues such as alfacalcidol are used when the kidneys cannot efficiently convert standard vitamin D, alongside adequate calcium intake and the broader bone support range.
- Persistent bone pain, difficulty walking, or a low-trauma fracture should prompt a blood test for vitamin D and calcium.
What osteomalacia is
Osteomalacia means bone that has lost its mineral hardness even though the underlying collagen framework stays intact. Hips, the lower back, and legs are affected most, and the result is dull, aching pain deep in the bone alongside generalised muscle weakness. It differs from osteoporosis, which reduces bone density without disrupting mineralisation itself.
What causes it
Severe, sustained vitamin D deficiency is the near-universal cause. Limited sun exposure, whether from indoor lifestyles, covering the skin, or weak seasonal sunlight, cuts the skin's own vitamin D production. Strict vegetarian or vegan diets add risk, since the richest natural food sources of vitamin D are animal-based. Malabsorption conditions such as coeliac disease, or bowel surgery that shortens the gut, can block vitamin D absorption even when dietary intake looks adequate.
How it is treated
Treatment restores vitamin D status directly. Alfacalcidol, an active vitamin D analogue, is often chosen when the kidneys cannot efficiently convert standard vitamin D, bypassing that conversion step entirely. Adequate calcium intake, part of the broader bone support range, is needed alongside vitamin D so bone can mineralise properly once the hormone is available. Bone pain and weakness typically start easing within weeks of correction, though full skeletal recovery takes longer.
When to see a doctor
See a doctor for persistent bone pain, difficulty walking, or a fracture that happened with little force behind it. A blood test for vitamin D and calcium is the usual first step, and treatment response is normally confirmed with follow-up levels.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.