25-year-old Priyanka was diagnosed with Major Depressive Disorder in 2015. And since then she’s been on a combination of medication and therapy to treat her depression.
“Over the years, it's been good, bad, and worse, on and off,” she says.
Recently, having switched psychiatrists altogether, Priyanka was recommended a routine checkup by her new doctor. While her thyroid, blood sugar, blood pressure, and B12 levels were fine, her Vitamin D levels were revealed to be severely low, prompting her doctor to prescribe her supplements along with her regular anti-depressants.
Priyanka isn’t the only one. Various studies done over the years show an overlap between people with depression and severe vitamin D deficiency, prompting a growing body of research connecting the two.
So, is there a link between Vitamin D deficiency and depression? Can seasonal depression in the winter be traced back to a lack of exposure to the sun?
FIT talks to Dr Manushree Gupta, Associate Professor, Department of Psychiatry, VMMC & Safdarjung Hospital to find out.
Vitamin D is a fat-soluble nutrient that helps absorb and use the calcium you consume, making it instrumental in maintaining bone health.
A deficiency in Vitamin D can not only lead to weakening or thinning of bones, bone softening (osteomalacia), low bone density (osteopenia), and osteoarthritis, but have also been linked to a host of other issues including cardiovascular and cognitive disorders.
Does Vitamin D Deficiency Cause Depression?
The exact reason for the connection between low levels of Vitamin D and depression is yet not conclusively known, but studies reinforce the hypothesis that there is a correlation between the two.
“People with depression are often also found to have a Vitamin D deficiency. Although the reason for the correlation is not certain, the co-existence exists.”Dr Manushree Gupta
The same study also points to vitamin D deficiency being associated with an increased risk or severity of depression, and how “supplementation of vitamin D may confer protection for depressed patients.”
Dr Gupta also explains how rectifying vitamin D deficiency in certain subsects of his patients with depression, especially elderly patients and those who spend most of their time indoors has significantly helped with their depression.
It must, however, be noted that there isn’t any evidence to suggest that vitamin D supplements will ‘cure’ depression.
Dr Gupta explains, “depression is a complex condition that can occur as a result of a combination of different reasons, and can’t be pegged to one cause or cure”.
It can often be concurrent and relapses could be due to many different reasons.
Interestingly Dr Gupta also adds that vitamin D, when added to antidepressants, significantly substantiates the effectiveness of the antidepressants.
'Winter blues' and the Lack of Sunlight
Could this connection also be the reason people experience seasonal depression in the winters when exposure to sunlight is limited?
Well, yes, and no.
Seasonal Affective Disorder, or SAD describes the lethargy and feelings of sadness and hopelessness that come when the weather forces people to spend more time indoors, with little opportunity for exposure to natural light.
Dr Gupta explains that seasonal depression—a phenomenon that is particularly experienced in winter by people in colder countries—can be attributed to a lack of exposure to sunlight and low absorption of UVB rays.
“In winters the lack of sunlight leads to a lack of absorption of UVB rays that creates certain changes in the brain and affects the body’s supply of melatonin. This imbalance contributes to symptoms of seasonal affective disorder (SAD) in winters."Dr Manushree Gupta
While not directly linked to vitamin D, SAD in winters is triggered by the lack of exposure to sunlight.
Does That Mean People in Tropical Countries Like India Don't Have to Worry?
In India, Vitamin D deficiency isn’t exactly on top of our list of health concerns.
For one, very few Indians will actually get their Vitamin D levels tested. This is because of the misconception that as a tropical country that gets lots of sunshine all year round, we could hardly be lacking sun explore.
The reality, however, is that India gets lots of sunlight, but the same can’t be said about Indians.
A pan-India study conducted by Dr Sanjiv Goel , M.S., MCH (ORTHO), Guardian Hospital, Jalandhar, in May 2020, suggested that 76 percent of the Indian population suffer from Vitamin D deficiency or insufficiency,
One reason for this could be the pandemic, and the subsequent lockdown that forced most of us indoors for months together. There is also the more culturally rooted reason of Indians and our general aversion to being in the sun for fear of tanning.
Yet another reason could be that the higher levels of melanin—like in most Indian skin tones—actually make it harder for the body to absorb Ultra Violet B rays of the sun and produce vitamin D.
The darker you are, the more melanin you have, and the more melanin you have, the longer it takes for your body to absorb UVB rays from sun exposure, making most Indians more prone to vitamin D deficiency.
Other Sources of Vitamin D
Vitamin D isn’t called the ‘Sunshine Vitamin’ for no reason. The sun still remains the best source of vitamin D. But if you’re not getting enough time in the sun, you could turn to these other alternative sources of Vitamin D.
- Seafood such as Salmon, Sardines, Herrings, Tuna
- Mushrooms
- Egg yolks
- Yogurt and Cheese
- Foods artificially fortified with vitamin D, like some brands of milk, and orange juice
- Supplements such as cod liver oil capsules
- Injectable Vitamin D supplements. (In case of severe deficiency, to be taken under medical supervision)
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