Vitamin D and Depression
Over the past decade there have been numerous scientific studies touting vitamin D as the wonder vitamin, finding it capable of fighting everything from cancer to depression. But do vitamin D levels really affect mental health? Actually, vitamin D deficiency has been associated with a variety psychiatric conditions, most notably depressive disorders, schizophrenia, and Alzheimer's disease. This is most likely due to the fact that vitamin D activates genes that release neurotransmitters (such as dopamine and serotonin) that affect brain function and development. Additionally, studies have located vitamin D receptors in specific areas of the brain that are associated with depression.
There are several clinical trials that have found a link between vitamin D deficiency and mental illness. According to these studies, low levels of vitamin D are thought to be involved in anxiety, depression, schizophrenia, learning, memory, and social behavior. Much of this research has offered evidence that supplementing low levels of vitamin D can improve psychological well-being in many cases.
One type of depression that appears to be strongly associated with vitamin D is seasonal affective disorder (SAD), a mood disorder characterized by depressive symptoms during times of the year when there is relatively little sunshine. Research has found that the symptoms of SAD coincide with a reduction in vitamin D3, which in turn affects serotonin levels in the brain.
For years, vitamin D blood levels of 20 ng/mL - which stands for nanograms per milliliter - were considered within the normal range. These measurements are attained with a blood test measuring something called "25-hydroxy-vitamin D" or "OHD" for short. Recently, this figure has been adjusted and normal is now a level greater than 30 ng/mL. Additionally, researchers and clinicians suggest that the appropriate range is between 50 and 75 ng/mL. For people who test in the low range, the new recommendations for supplementation fall between 2,000 IU to 10,000 IU, with monitoring by blood testing every few months.
A study published in the journal Clinical Nutrition in October suggested that low levels of vitamin D are linked to an increased risk of depression in mid-life. The study, from the University College London in the UK, found that participants with vitamin D levels of at least 75 ng/mL had a 43% lower risk of depression, compared to people with vitamin D levels lower than 25 ng/mL. The researchers also found that higher vitamin D levels were associated with a 67% lower risk of panic, compared to the lower levels.
The current study is one of a number that have found an association between vitamin D status and symptoms of depression. In 2010, the US National Health and Nutrition Examination Survey found that people with vitamin D deficiency were at an 85% increased risk of having depression as compared with those with sufficient levels.
In the case of vitamin D, getting it from sunshine is the best source, however this can present a challenge. Some people have difficulty synthesizing vitamin D from the sun and many live in climates where there is relatively little sun for long periods of time. This is particularly problematic for people prone to seasonal effective disorder as lack of sun is thought to trigger episodes. As far as diet goes, most nutritionists concur that it is generally not possible to get enough amounts of vitamin D through food alone.
The best source of vitamin D is found in food from fish, like salmon, mackerel, tuna, and sardines. Cod liver oil is also a good source. However, because a lot fish has high levels of contaminants like mercury, the amount of fish you would have to eat to get enough Vitamin D could be hazardous to your health. If you're going to consume fortified foods like milk and breakfast cereals, you're probably better off taking a supplement.
In most cases, it's better to get your nutrition from foods instead of supplements, but there are exceptions to this. For one thing, it can be hard to get large doses of nutrients from food. If you are treating a medical or mental health condition with high amounts of a particular nutrient, you will need to use supplements.
Of course, vitamin D supplementation is only a part of a comprehensive treatment plan for depression. Any plan - whether based on pharmaceuticals or natural methods - should include psychotherapy. However, low levels of certain vitamins, such as vitamin D, can impair and prolong recovery from depression.
Fredricks, R. (2008). Healing and Wholeness: Complementary and Alternative Therapies for Mental Health. Bloomington, IN: Authorhouse. ASIN: B00BARVB96
Ganji1 V, Milone C, Cody MC, McCarty F, Wang, FT (2010). Serum vitamin D concentrations are related to depression in young adult US population: The Third National Health and Nutrition Examination Survey. International Archives of Medicine, 3:29. doi:10.1186/1755-7682-3-29
Maddock J, Berry DJ, Geoffroy MC, Power C, Hyppönen E. (2013). Vitamin D and common mental disorders in mid-life: cross-sectional and prospective findings. Clinical Nutrition, 32(5), 758-64. doi: 10.1016/j.clnu.2013.01.006