Osteomalacia
Osteomalacia is the softening of adult bones due to impaired mineralisation, almost always driven by a severe lack of vitamin D. Unlike osteoporosis, which thins bones that were once fully formed, osteomalacia affects the bone matrix itself. The result is dull, aching pain deep in the bones, generalised muscle weakness, and a tendency for hairline fractures with minimal trauma. Hips, lower back, and legs are most commonly affected.
Key points
- Severe, prolonged vitamin D deficiency softens the bone matrix itself, unlike osteoporosis, which simply thins bone that had already formed normally.
- Avoiding sun exposure, wearing full-coverage clothing, prolonged air-conditioned indoor living or a vegan diet can each restrict vitamin D levels.
- Alfacalcidol, an active vitamin D analogue, is often used when the kidneys cannot convert standard vitamin D, skipping that step altogether.
Why vitamin D deficiency runs deep
Despite abundant sunshine in many warm climates, osteomalacia remains a genuine clinical problem. Strict sun avoidance, full skin coverage for cultural or cosmetic reasons, and heavily air-conditioned indoor lifestyles all reduce skin synthesis. Strict vegetarian and vegan diets add dietary risk because the richest food sources of vitamin D are animal-based. Malabsorption conditions such as coeliac disease or post-surgical short bowel compound the problem further.
Treatment centres on restoring vitamin D status. Active vitamin D analogues such as alfacalcidol are often chosen when the kidneys cannot efficiently convert standard vitamin D, bypassing that conversion step entirely. Broader bone health support, including adequate calcium intake, is needed alongside vitamin D to allow proper bone mineralisation. Bone pain and weakness typically begin to ease within weeks once levels are corrected, though full skeletal recovery takes longer.
If you experience persistent bone pain, difficulty walking, or a low-trauma fracture, a blood test for vitamin D and calcium levels is the logical first step.