According to estimates, 50% of people worldwide have low vitamin D levels, with the highest prevalence among adults over 60, those with a dark complexion, and those who are obese (1).
Vitamin D deficiency has also been linked in recent studies to psychological conditions like sadness, anxiety and seasonal affective disorder. It has also been suggested that low levels of Vitamin D may be linked to depressive symptoms. It is so since it functions as a steroid in many brain processes, such as neuroprotection, regulation of neurotrophic factors, neuroplasticity, brain development, and neuroimmunomodulation (3). The correlation, not the causation, between the two conditions, maybe because many individuals at risk for depression are also at risk for vitamin D deficiency.
Depression can cause various symptoms, including decreased productivity, trouble concentrating, irritability, weariness, appetite loss, low self-esteem, feelings of worthlessness, suicidal thoughts, and changes in body weight (4).
Not all, but some cross-sectional clinical and epidemiologic studies have discovered a substantial correlation between low Vitamin D levels and greater levels of depressive symptoms or a depression diagnosis. There is evidence that patients with depression have low Vitamin D levels. The relationship between the brain's 1-alpha-hydroxylase enzymes and Vitamin D receptors may indicate that Vitamin D plays a specific role in the central nervous system (5).
SEASONAL DEPRESSION AND VITAMIN D
Sunlight is the main source of vitamin D, which is why it is sometimes known as the ‘sunshine vitamin’ (2).
Climate and weather fluctuations are linked to seasonal depression. Changes in solar exposure affect the body's vital hormone levels, including serotonin and melatonin. The level of serotonin depends on the availability of Vitamin D, which is required for synthesising the hormone. As a result, as exposure to sunshine declines, so do Vitamin D levels and, subsequently, serotonin levels. This signifies the relationship between Vitamin D and seasonal depression (6).
Vitamin D can also be obtained from various dietary sources like red meat, liver, egg yolks, and oily fish like sardines, mackerel, and salmon.
Contrary to popular belief, When people say sunlight provides vitamin D, they are actually talking about the UV rays you receive from the sunlight. Our skin naturally contains a precursor to vitamin D. When exposed to UV rays, the precursor is transformed into a molecule called vitamin D3 (7).
Vitamin D's fundamental function is maintaining proper amounts of calcium and phosphorus for several metabolic processes, regulating bone and muscular strength, healthy immune system operation, and neuroprotection (8). People with depression receive relatively little sunlight because they spend most of their time indoors.
To meet your body's Vitamin D needs, spend at least 10-15 minutes outside three days a week (9).
RECOMMENDED DOSAGE OF VITAMIN D
The recommended daily allowance (RDA) for individuals is 600 IU of Vitamin D, increasing intake to 800 IU for those over 70. Studies have shown that Vitamin D supplements up to 2000 IU significantly reduce depression in pregnant women (10). According to the National Institutes of Health, it is safe to take up to 4000 IU of Vitamin D for depression (8).
Check your Vitamin D levels if any of these depression-like symptoms apply to you. Your doctor will do a test to find out how much of the Vitamin is in your blood. Getting in touch with a reputable healthcare provider if you're displaying signs of depression is crucial. Fortunately, it's simple to obtain Vitamin D by either taking supplements, getting more sunlight, or including foods high in Vitamin D in your diet.