The clinically depressed women who participated in the study received treatment for their vitamin D deficiency without changing any of their antidepressant medication regimes or any other influential factors in their environment. The authors consequently concluded that fixing the deficiency of vitamin D alone might have beneficial effects on depression.
Sonal Pathak, MD, an endocrinologist at Bayhealth Medical Center in Dover, Delaware, said:
"Vitamin D may have an as-yet-unproven effect on mood, and its deficiency may exacerbate depression. If this association is confirmed, it may improve how we treat depression".
Three women diagnosed with severe depression, between the ages of 42 and 66, were selected to test Pathak's theory. Each of the three women was undergoing antidepressant therapy, while also being treated for either Type 2 diabetes or hypothyroidism (an underactive thyroid).
A 25-hydroxyvitamin D blood test was given to the patients to test for vitamin D deficiency. The patients said they had low vitamin D intake and poor sun exposure, which increases the absorption of the vitamin. Sun exposure encourages the synthesis of vitamin D by the skin.
The test confirmed that all the women did have low levels of vitamin D, ranging from 8.9 to 14.5 nanograms per milliliter (ng/mL). According to The Endocrine Society, any level below 21 ng/mL means vitamin D deficiency. Anything above 30 ng/mL is thought to be a normal vitamin D level.
For a period of between 8 to 12 weeks the participants were given oral vitamin D replacement therapy, which brought their vitamin levels back to normal. The study abstract states their levels after the therapy ranged from 32 to 38 ng/mL.
The Beck Depression Inventory, a 21-item questionnaire scoring symptoms of depression and sadness, was given to the women for them to fill in. They showed substantial improvement in their depression after their vitamin D levels were back to normal.
The test score has four general levels, 0 to 9 means the lowest level of sadness, 10 to 18 suggests mild depression, 19 to 29 indicates moderate depression, while 30 to 63 means that the patient has severe depression.
Below are some highlighted data from the study:
- First woman - she initially had a score of 32. This improved to 12 on overall sadness after her vitamin D levels were adequate
- Second woman - her score improved from 28 to 8
- Third woman - her scored went from an initial 21 to 16
"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."
Written by Sarah Glynn