"low Vit D levels lead to more, worse and prolonged depression & anxiety"
This isn't entirely accurate, and I'm going to quibble a bit with it and cite a study, but TLDR exercising outside during the daytime is probably better than just supplements of D.
To be clear I myself take Vitamin D because it may have benefits, including for mental health, so this isn't me trying to say D couldn't help with depression, just that that particular statement is a little misleading in that we don't have the best evidence for it.
There's definitely some evidence that Vitamin D levels are correlated with worse depression scores, but no studies about deficiency causing it to be worse; I suspect few people would choose to sign up for a study to make they depression worse, tbh. Anyway, the closest are studies of supplements to Vitamin D levels in depressed people, and the results there are mixed.
For example a study called "Effect of vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised clinical trial" in the British Journal of Psychiatry found no statistically significant differences in depression inventories.
I believe there is some meta analysis that shows that Vitamin D supplementation may benefit people with clinically significant depression scores. But if you are badly depressed, you should consider moderate mixed aerobic and anaerobic exercise outside during the day, which gets you sunlight for vitamin D, exercise, and light exposure.
Regardless of whether Vitamin D makes a difference, exercise and light exposure both can help with depression (or in the case of the latter at least Seasonal Affective Disorder, which can cause or exacerbate depression), and the evidence there is more substantial. For the record, light therapy boxes seem to help with SAD even when they generally have low UV so little chance that it's vitamin D that's making the difference.
This isn't entirely accurate, and I'm going to quibble a bit with it and cite a study, but TLDR exercising outside during the daytime is probably better than just supplements of D.
To be clear I myself take Vitamin D because it may have benefits, including for mental health, so this isn't me trying to say D couldn't help with depression, just that that particular statement is a little misleading in that we don't have the best evidence for it.
There's definitely some evidence that Vitamin D levels are correlated with worse depression scores, but no studies about deficiency causing it to be worse; I suspect few people would choose to sign up for a study to make they depression worse, tbh. Anyway, the closest are studies of supplements to Vitamin D levels in depressed people, and the results there are mixed.
For example a study called "Effect of vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised clinical trial" in the British Journal of Psychiatry found no statistically significant differences in depression inventories.
I believe there is some meta analysis that shows that Vitamin D supplementation may benefit people with clinically significant depression scores. But if you are badly depressed, you should consider moderate mixed aerobic and anaerobic exercise outside during the day, which gets you sunlight for vitamin D, exercise, and light exposure.
Regardless of whether Vitamin D makes a difference, exercise and light exposure both can help with depression (or in the case of the latter at least Seasonal Affective Disorder, which can cause or exacerbate depression), and the evidence there is more substantial. For the record, light therapy boxes seem to help with SAD even when they generally have low UV so little chance that it's vitamin D that's making the difference.