The Effectiveness of Vitamin D Supplementation in Patients With End-stage Knee Osteoarthritis
Status:
Recruiting
Trial end date:
2025-11-30
Target enrollment:
Participant gender:
Summary
Osteoarthritis (OA) knee is one of the commonest chronic degenerative conditions. It causes
disability in elderlies due to pain and stiffness. The prevalence of radiologic knee
osteoarthritis increases in proportion to age, reaching an astounding 64.1% for patients who
are over 60 years of age. In 2021, there were over 26,000 patients on the Hospital Authority
(HA) waiting list for knee total knee replacement (TKR) and with only 4300 TKRs performed,
the nominal waiting time for TKR was almost 89 months.
Low vitamin D can adversely affect cartilage thickness and study suggested that low serum
vitamin D is associated with increased radiographic knee OA progression. A systematic review
concluded that vitamin D supplements can improve pain and function in patients with knee OA.
Vitamin D has long been recognized for its effect on musculoskeletal health and increasing
attention has been focused for its effect on muscle function. Vitamin D have a direct effect
on muscle hypertrophy by acting on specific vitamin D receptors (VDRs) on myocytes, and
sufficient levels of vitamin D in patients have been found to correlate with an increase in
the size, number, and strength of muscle fibres. Vitamin D also seems to exert beneficial
effects by its interplay with myokines such as myostatin and irisin.
One study also showed that muscle nuclear VDR was increased by 30% and augmented muscle fibre
size by 10% in elderly females (mean age of 78 years) taking vitamin D orally at a rate of
100 µg/day (4000 IU/day) for 4 months.
This will be a double-blinded RCT investigating the effect of vitamin D supplements or knee
muscle strength, physical function, pain symptoms and, sarcopenia status. The study will be a
follow-up study with assessment at baseline, 3- ,6-and 12-months post vitamin D intervention.