Osteomalacia is characterised by impaired mineralisation of bone, usually caused by vitamin D deficiency but can also be secondary to several other rarer conditions.  It is associated with low BMD, as measured by DXA, and fractures.⁶ Phosphate wasting caused by the use of TDF may be associated with osteomalacia. The clinical presentation is characterised by bone pain and inability to walk due to microfractures.²⁴  Laboratory findings in osteomalacia are dependent on the cause and can include a low serum vitamin D level, hypophosphataemia and an elevated serum alkaline phosphatase level.  As DXA scanning may not differentiate between osteoporosis and osteomalacia, the presence of osteomalacia may not be appreciated.²⁵ Specialist referral is indicated if this condition is suspected.