Calcium plus vitamin D supplementation may not have joint benefits: RCT data
The randomised controlled study, published in the Journal of the Academy of Nutrition and Dietetics, analysed the effect of calcium and vitamin D supplementation on joint symptoms in postmenopausal women - finding that intake of a supplement had no significant effect on the severity of joint symptoms.
Led by Dr Rowan Chlebowski at Harbor-UCLA Medical Center, USA, the research team noted that low calcium and vitamin D deficiency has been suggested to have negative effects on joint symptoms, however the team said that results from full-scale randomised trials to test whether supplementation can reverse such effects have been sparse.
"In the current study, we addressed for the first time in a full-scale, randomized clinical trial setting, the clinically relevant question of whether postmenopausal women using calcium and vitamin D supplements in currently recommended dosage would experience any favourable effect on joint pain or swelling, common symptoms in postmenopausal women," explained Chlebowski.
"Joint symptoms are relatively common in postmenopausal women," he explained. "However, daily supplementation with 1,000 mg of calcium carbonate and 400 IU of vitamin D3 in a randomized, placebo-controlled clinical trial setting did not reduce the self-reported frequency or severity of joint symptoms."
"Women using calcium and vitamin D supplementation at this dose should not anticipate joint symptom relief," the team concluded.
However, Chlebowski and his colleagues added that their findings do go against current recommendations for vitamin D intakes for bone health and fracture risk reduction.
The researchers used data from the 36,282 strong Women's Health Initiative (WHI) calcium plus vitamin D supplementation trial, to identify a subgroup of 1,911 postmenopausal women for the current study. Women had been randomised to receive 1000mg calcium carbonate with 400 IU vitamin D3 daily or placebo and had undergone serial joint symptom assessment.
The team reported that joint pain and swelling at baseline entry was comparable between the daily supplement use and placebo groups.
After two years, further analysis revealed no statistically significant difference for the frequency of joint pain or swelling, they said.
"The severity of joint pain or joint swelling also was similar in the supplement and placebo groups after 2 years," they team added.
Source: Journal of the Academy of Nutrition and Dietetics
Published online ahead of print, doi: 10.1016/j.jand.2013.06.007
"Calcium Plus Vitamin D Supplementation and Joint Symptoms in Postmenopausal Women in the Women’s Health Initiative Randomized Trial "
Authors: Rowan T. Chlebowski, Mary Pettinger, Karen C. Johnson, et al
Posted by Seth Kaplan,