Does Vitamin D deficiency lead to Depression?

What Is Vitamin D Deficiency?

We all have heard of Vitamin D deficiency. It is so common that you and I might also have this deficiency. Vitamin D deficiency occurs when the body lacks adequate levels of vitamin D, a nutrient crucial for absorbing calcium and phosphorus, maintaining bone strength, and supporting muscle, nerve, and immune function. Studies reveal that approximately 1 billion people globally have vitamin D deficiency, with about 35% of adults in the United States affected.​

Causes of Vitamin D Deficiency

There are two major causes:

1. Lack of sufficient sunlight exposure, which reduces the skin’s production of vitamin D3 (cholecalciferol).​

2. Limited intake of vitamin D-rich foods (fatty fish, egg yolks, fortified milk, mushrooms, fish liver oils, etc).​

   
   

There can also be other contributors, including medical conditions (liver disease, kidney problems, obesity, etc.), increased skin melanin (darker skin), aging, certain medications, and more.

Can Vitamin D Deficiency Cause Depression?

Indians generally have a darker skin tone, which can increase the risk of vitamin D deficiency. Vitamin D deficiency can lead to conditions such as rickets in children and osteoporosis, bone pain, weakness, and more in adults. While these are all physical conditions, vitamin D deficiency leads to a major mental health condition- Depression.

How is Vitamin D deficiency linked to Depression?

Vitamin D has specific receptors found in certain parts of the brain, particularly those involved in mood regulation, such as the prefrontal cortex and hippocampus. Vitamin D acts as a neurosteroid, supporting neuron health and regulating expression of neurotrophic factors such as NGF and BDNF, both essential for neurogenesis and synaptic plasticity. Deficiency of vitamin D can disrupt the normal functioning of the HPA axis or the hypothalamic-pituitary-adrenal axis, which is important for neurotransmitter synthesis and stress adaptation. Low vitamin D levels may also increase neuroinflammation and oxidative stress, both implicated in depression.​

A meta-analysis of randomized controlled trials was conducted, confirming that vitamin D supplementation produces a statistically significant, moderate reduction in depressive symptoms, especially in individuals already deficient at baseline. This effect is stronger in long-term interventions and in people with medical comorbidities. However, it is very important to note that the reduction in depression severity is of minimal clinical importance as the difference is not so great, indicating that vitamin D is helpful mainly as an adjunct, not as a primary treatment for depression.

Most studies point to a correlation between vitamin D and depression. Depression may lead to behaviors such as social isolation, which involves staying indoors or a lack of appetite, that can worsen vitamin D deficiency. The symptoms of depression (fatigue, low mood, poor appetite, etc.) often overlap with those of vitamin D deficiency. High-risk groups for both conditions include older adults, adolescents, people with obesity, and those with chronic illnesses, which are often due to shared factors like reduced outdoor activity and poor nutrition. This is why it is often very difficult to diagnose whether vitamin D deficiency can result in depression in individuals.

Proper vitamin D levels are very important for the healthy functioning of individuals throughout their lifespan. It may be a contributing factor to mental illness, but that isn’t always the case.

Managing Vitamin D Deficiency and Depression

Medications and Supplements

• The primary step is screening for vitamin D levels in individuals with depressive symptoms or at risk for deficiency.​

• Oral vitamin D supplements are often prescribed, with typical doses ranging from 2,000 IU to 50,000 IU per week, depending on the severity of deficiency and individual health status.​ These should only be used under the advice of a healthcare professional.

• Supplementation duration can vary. Follow the course prescribed by your healthcare professional. Long-term regimens (often over several months) show greater improvements in depressive symptoms than short-term courses.​

• It's essential to monitor serum vitamin D and calcium levels during supplementation to prevent toxicity, particularly for individuals with renal insufficiency or metabolic risk factors.

Lifestyle Changes

• Increase the intake of vitamin D-rich foods, such as fatty fish, fish liver oils, egg yolks, fortified dairy or plant milks, and UV-exposed mushrooms, supporting improved vitamin D levels.​

• Vitamin D deficiency can be reduced largely through safe exposure to sunlight for 10–30 minutes, several times a week. You can use sunscreen and other protections to prevent skin damage.​

• Physical activity and regular exercise, such as yoga, running, aerobics, etc., along with proper sleep hygiene, are recommended for both improving mood and supporting metabolic functioning.

Mental health management

If the individual is suffering from depression or showing signs of low mood, irritability, and so on, it is necessary to consult a psychologist. Therapeutic interventions such as Cognitive Behavioral Therapy, counseling, other therapies, and, in certain cases, antidepressants can also help deal with the symptoms effectively.

Vitamin D supplementation can be considered a supportive, adjunctive therapy and is not a substitute for these psychological modalities.

Several studies are being conducted to understand the role of vitamin D deficiency in several physical and mental illnesses, such as autoimmune disorders, metabolic disorders, and mood disorders. 

If you haven’t taken a blood test in a while, we urge you to do one immediately. This will enable you to identify underlying deficiencies or potential risks of developing such deficiencies. Supplements must be taken only on the advice of a licensed healthcare professional.

If you notice yourself or someone you know experiencing symptoms like low mood, irritability, reduced appetite, and others, book your session with Koott today. Through the right diagnosis and interventions, we promise to improve your life and wellbeing.