New research out of the Netherlands suggests that vitamin D deficiency may lead to greater risk of bone loss in those with systemic lupus erythematosus.
Systemic lupus erythematosus (SLE) is an autoimmune disease where the body’s own immune cells mistakenly attack healthy cells in areas including the joints, kidneys, and skin, causing inflammation, pain, swelling, fatigue, arthritis, and fevers. The cause of SLE is not understood.
Vitamin D deficiency is common in patients with SLE. One reason is that some patients with SLE are sensitive to sunlight and avoid sun exposure, thus leading to vitamin D deficiency. Researchers are also interested if vitamin D deficiency is a cause of SLE or makes the disease worse, which would also explain why vitamin D deficiency is common in SLE. However, more research is needed to further understand this relationship.
Bone loss is also common in patients with SLE. This is because one of the treatments used in SLE is glucocorticoids. Glucocorticoids are a type of hormone drug that can help manage SLE, but also can lead to increased bone loss.
In the present study, researchers wanted to know if not only glucocorticoid use was associated with bone loss in SLE, but if vitamin D deficiency might be associated with bone loss, too.
The researchers enrolled 126 patients with SLE into their study and followed them for 6 years. At baseline, they looked at the patients’ vitamin D levels and bone mineral density (BMD) and whether they were taking glucocorticoids.
As somewhat expected, the researchers found that patients taking at least 7.5 mg/day of glucocorticoids compared with those receiving less than 7.5 mg/day at baseline were more likely to experience decreases in BMD in the spine over the 6 year study. However, they didn’t notice a similar relation in BMD of the hip.
The researchers also noticed that vitamin D deficiency at baseline was associated with larger decreases in BMD. Those with low vitamin D levels lost more BMD over the 6 year period for both the hip and spine.
The researchers stated, “Lower serum levels of 25(OH)D [vitamin D] were associated with BMD loss both at the lumbar spine and the hip, while BMI loss and the use of antimalarials were associated with BMD loss at the hip.”
The researchers call for screening for vitamin D deficiency and osteoporosis and the establishment of prevention measures in patients taking higher doses of glucocorticoids.