Three case studies of women with moderate to severe depression showed substantial improvement in their symptoms after they received treatment for a vitamin D deficiency, a new study finds.
“Vitamin D may have an as-yet-unproven effect on mood, and its deficiency may exacerbate depression,” said Sonal Pathak, M.D., an endocrinologist at Bayhealth Medical Center in Dover, Del. “If this association is confirmed, it may improve how we treat depression.”
At the Endocrine Society’s 94th Annual Meeting in Houston, Pathak presented the research findings of three women, ranging in age from 42 to 66, who had been diagnosed with clinical depression and were taking antidepressants. The women also were being treated for either Type 2 diabetes or an underactive thyroid (hypothyroidism).
Because the women had risk factors for vitamin D deficiency, such as low vitamin D intake and poor sun exposure, they each underwent a 25-hydroxyvitamin D blood test.
For all three women, the test found low levels of vitamin D, ranging from 8.9 to 14.5 nanograms per milliliter (ng/mL). Levels below 21 ng/mL are considered deficient, while normal vitamin D levels are above 30 ng/mL, according to The Endocrine Society.
Over eight to 12 weeks, oral vitamin D replacement therapy restored the women’s vitamin D status to normal. Their levels after treatment ranged from 32 to 38 ng/mL, according to the researchers.
After treatment, all three women reported significant improvement in their depression, according to the Beck Depression Inventory. This 21-item questionnaire scores the severity of sadness and other symptoms of depression. A score of 0 to 9 indicates minimal depression; 10 to 18 mild depression; 19 to 29 moderate depression; and 30 to 63 severe depression.
One woman’s depression score improved from 32 to 12, a change from severe to mild depression. Another woman’s score fell from 26 to 8, indicating she now had minimal symptoms of depression. The third patient’s score of 21 improved after vitamin D treatment to 16, also in the mild range.
Other studies have suggested that vitamin D has an effect on mood and depression, but there is a need for large, randomized controlled clinical trials to prove whether there is a real relationship, Pathak said.
“Screening at-risk depressed patients for vitamin D deficiency and treating it appropriately may be an easy and cost-effective adjunct to mainstream therapies for depression,” she said.