Could Nutrient Deficiencies Be Contributing to My Anxiety?
Anxiety is a complex condition and is rarely caused by a single factor. However, in some cases, underlying nutrient deficiencies may contribute to symptoms that overlap with or worsen feelings of anxiety.
This does not mean that everyone with anxiety has a nutrient deficiency, nor does it mean that correcting a deficiency will completely resolve anxiety symptoms.
However, ensuring that key nutrients are present at healthy levels is an important part of supporting overall mental and physical wellbeing.
Why Nutrients Matter for Mental Health
The brain depends on a steady supply of nutrients to support:
Energy production
Neurotransmitter synthesis - serotonin, dopamine, GABA
Nervous system function
Stress resilience
Cognitive performance
When nutrient levels become depleted, the body may struggle to function optimally.
This can sometimes contribute to symptoms such as:
Fatigue
Poor concentration
Irritability
Low mood
Increased stress sensitivity
Feelings of anxiety
Iron Deficiency
Iron is essential for oxygen transport and energy production.
Low iron levels can cause:
Fatigue
Weakness
Brain fog
Shortness of breath
Heart palpitations
Some of these symptoms can feel very similar to anxiety.
Iron deficiency is particularly common in:
Menstruating women
Pregnant women
Vegetarians and vegans
Individuals with digestive conditions that affect absorption
If iron deficiency is suspected, testing should always be carried out before taking iron supplements.
Vitamin B12
Vitamin B12 plays an important role in nervous system function and neurological health.
Low levels may contribute to:
Fatigue
Poor concentration
Memory difficulties
Low mood
Numbness or tingling
People at increased risk include:
Vegans
Vegetarians
Older adults
Individuals with digestive disorders
Because symptoms can develop gradually, deficiency may go unnoticed for some time.
Folate
Folate works closely with vitamin B12 and is involved in neurotransmitter production.
Low folate levels may contribute to:
Fatigue
Reduced resilience to stress
Changes in mood
Poor concentration
Leafy green vegetables, legumes and fortified foods are important dietary sources.
Magnesium
Magnesium is involved in hundreds of biochemical reactions throughout the body, including those related to muscle relaxation and nervous system regulation.
Some people with low magnesium levels may experience:
Muscle tension
Poor sleep
Increased stress sensitivity
Fatigue
While magnesium supplements are often promoted online for anxiety, it is important to remember that supplementation is most beneficial when a genuine deficiency or insufficiency exists.
Vitamin D
Vitamin D receptors are found throughout the brain and nervous system.
Low vitamin D levels have been associated with:
Low mood
Reduced wellbeing
Fatigue
In the UK, vitamin D deficiency is relatively common, particularly during autumn and winter when sunlight exposure is limited.
Government guidance recommends vitamin D supplementation for many adults during these months.
Food First: Building a Nutrient-Rich Diet
Before focusing on supplements, it is worth considering the foundations of your diet.
A nutrient-rich eating pattern should include:
Colourful vegetables
Fruit
Whole grains
Beans and lentils
Nuts and seeds
Oily fish
Eggs
Dairy or fortified alternatives
A varied diet provides a wide range of nutrients that work together to support overall health.
Should You Get Tested?
If you experience ongoing fatigue, brain fog, low mood or anxiety symptoms that do not seem to improve, it may be worth discussing testing with your healthcare provider.
Depending on your symptoms and medical history, they may assess:
Iron status
Vitamin B12
Folate
Vitamin D
Other relevant markers
Testing can help identify whether a deficiency is present and guide appropriate treatment.
The Bottom Line
Nutrient deficiencies are unlikely to be the sole cause of anxiety, but they can sometimes contribute to symptoms that affect how we feel physically and emotionally.
Addressing deficiencies, eating a nutrient-rich diet and supporting overall health may help create a stronger foundation for mental wellbeing.
If you are concerned about your nutrient status, a GP can run a blood test for some nutrient markers or our Personalised Diet Review can assess your intake of all minerals and vitamins which is a great insight into how much you are consuming through the foods you eat. This data is a great starting point for making changes to your diet in order to support mental and physical health.
References
Boyle, N.B., Lawton, C. and Dye, L. (2017) 'The effects of magnesium supplementation on subjective anxiety and stress: A systematic review', Nutrients, 9(5), p. 429
Shams, A., Iqbal, N., Arif, S.K., Wusqa, U., Ilyas, N. and Rehman, A.F. (2025) 'Evaluating the impact of vitamin D supplementation on anxiety and depression: A systematic review of RCTs', Review Journal Neurological & Medical Sciences Review
Marx, W., Moseley, G., Berk, M. and Jacka, F. (2017) 'Nutritional psychiatry: The present state of the evidence', Proceedings of the Nutrition Society, 76(4), pp. 427–436.
O'Leary, F. and Samman, S. (2010) 'Vitamin B12 in health and disease', Nutrients, 2(3), pp. 299–316.
