Vitamin D Deficiency And Depression

Vitamin D Deficiency Is Associated With an Increased Likelihood of Incident Depression
Journal: JAMDA

Vitamin B12 deficiency and, as this study shows, low levels of vitamin D may cause symptoms of depression.

If pirates taught us anything about health, it’s that some symptoms can be fixed by adding a single nutrient into our diet. Scurvy may not explain every case of bleeding gums, but it proves that sometimes a simple dietary addition (i.e. vitamin C) is a treatment worth considering.

In this study researchers examined the link between vitamin D levels and depression in a group of 4,000 people living in a sun-deprived country: Ireland. Depressive symptoms and vitamin D levels were recorded and then re-recorded 4 years later– it’s this follow-up that makes the study interesting to me.

Vitamin D deficiency (less than 30 nmol/L in a blood test) was seen to increase a person’s risk for depression by 75%(!) during the four year follow-up period. This remained true regardless of age or gender, even after controlling for other potential issues that might cause depression like physical inactivity and chronic disease burden. For comparison, studies have shown that genetics only account for a 40-50% increased risk.

I should mention that this doesn’t suggest that depression is always caused by a lack of vitamin D–we know that it can be caused by things ranging from Winter, to chemical-exposure, to grief. Neither does this result mean that all people with low levels of vitamin D will feel depressed.

This does, however, suggest that supplementing with vitamin D, or spending more time in the sun may reduce symptoms of depression. This might also explain why Seasonal Affective Disorder (SAD) improves with UV light therapy.

TAKEAWAY
This study suggests that vitamin D deficiency (less than 30 nmol/L) might be the reason why some people struggle with depressive symptoms. Good news is that it’s an easy blood test to determine if supplementing is the right call. Or, find the sun.