Background: Knee osteoarthritis (KOA) is a chronic, degenerative knee joint disorder associated with inflammation, pain, stiffness, and reduced functional abilities, thereby impacting the patient’s quality of life. The prevalence of KOA is growing rapidly in India and around the globe, even in younger populations. Vitamin D plays a crucial role in musculoskeletal health and deficiency of this vitamin is highly prevalent across the age groups impacted by KOA. Consumption of vitamin D rich foods along with functional foods possessing antioxidant and analgesic properties needs to be explored as a potentially novel, low cost dietary strategy for the prevention and management of chronic musculoskeletal disorders such as KOA.
Objective: To assess the effect of vitamin D3 and Virgin Coconut Oil (VCNO) supplementation on vitamin D3 status, cartilage degeneration, inflammatory status, and functional abilities in early KOA.
Methods: One hundred vitamin D deficient, age and gender-matched adults afflicted by early KOA (30-65yrs) were selected purposively from K. J. Somaiya Hospital and Research Centre, Mumbai, India after obtaining ethical clearance from the institute. Informed consent was obtained from the participants. They were then counselled on making required dietary modifications, with due emphasis on vitamin D3 rich foods, and were given an at-home KOA exercise program. The participants were divided equally into two experimental groups: E1 (n=50) and E2 (n=50), with equal number of males and females in each group. The groups were either supplemented with Vitamin D3 alone (group E1) or Vitamin D3 + VCNO (group E2). All the participants were assessed for vitamin D status (serum 25 (OH) D levels (CLIA), Vitamin D3 intake (3-day diet recall and FFQ), pain (VAS), stiffness, functional abilities (WOMAC and 6 MWT), and inflammation (ESR and serum CRP). The cartilage marker (s-COMP (ELISA)) was assessed only in a subset of participants (n =40) from each group, both pre and post intervention. Data were analyzed using SPSS 16.0.
Results: A significant rise in Vitamin D3 intake and serum vitamin D3 levels (p<.001) was observed post-supplementation in both groups. sCOMP (<.001), ESR, and serum CRP (<.001) were significantly reduced in both the groups, indicating a decline in cartilage degeneration and inflammatory status. VAS score (<.001) was significantly reduced in both groups, indicating reduced pain intensity. Total WOMAC score (p<.001) was significantly reduced, with a highly significant improvement in the distance covered during the 6 MWT (<.001), indicating improved functional abilities. The mean difference of effect in all the above parameters was higher in the vitamin D3 and VCNO supplementation group (E2) than the group which received vitamin D3 alone (E1).
Conclusion: Supplementation of vitamin D3 along with VCNO could be an effective strategy for delaying the progression of KOA by reducing cartilage degeneration, inflammation and pain, as well as improving functional abilities. Thus, simultaneous improvement of vitamin D3 status and oxidative stress should be considered in early KOA management. Non-conventional antioxidant and anti-inflammatory functional foods such as VCNO could be further explored.
Key words: Knee osteoarthritis, vitamin D, virgin coconut oil, anti-inflammatory, functional food, functional abilities, cartilage degeneration, inflammation, WOMAC, sCOMP.