It's fair to say that most people experience an emotional lift when the days are bright and sunny, but that effect may result from more than just an emotional boost and may, in fact, have a physiological basis.

The reason for this is because exposure to the sun helps our bodies produce vitamin D, also known as the sunshine vitamin, a necessary nutrient that is not prevalent in many of the foods we eat. Consequently, vitamin D deficiencies are not uncommon, especially in people who avoid sun exposure. Doctors believe that these deficiencies can lead to numerous physical health problems. Now it seems that there may be emotional and psychological consequences as well.

New research focusing on older women suggests that a lack of vitamin D increases a woman's chances of experiencing depression symptoms when compared to women who consumed adequate levels of vitamin D, mainly through supplementation.

In the study in question, published in the American Journal of Clinical Nutrition, researchers followed nearly 82,000 women between the ages of 50 and 79 years. Participants were divided into two groups: those that consumed 800 international units (IU) of vitamin D per day (high consumption), and those that consumed less than 100 IU per day (low consumption).

Baseline vitamin D intake levels were measured while also controlling for the amount of sunlight exposure they received. After three years, depressive symptoms were measured again and then compared to the baseline levels. After controlling for various factors, including age and physical activity, scientists were able to arrive at their conclusions.

What they found was that the women in the high consumption group were 20% less likely to experience depressive symptoms compared to the low consumption group. When women had no depression at the beginning of the study, consumption of 400 IU or more of vitamin D through the foods they ate was also linked to a 20% lower risk of depressive symptoms over time (3 years) when compared to the low consumption group.

The results are intriguing because they suggest an easy and accessible way to address depression without the use of medication or therapeutic intervention. While the authors stress that more work needs to be done, including clinical trials to confirm the relationship, the findings nonetheless point to a promising direction in the treatment and prevention of depression that may include a healthy diet.

Depression is a serious condition that should not be ignored. Depression can greatly reduce a person's quality of life and can have serious consequences on their physical and emotional health. In severe instances, it can even prevent a person from functioning normally in their daily activities. If you or someone you know is suffering from depression, seek out professional help as soon as possible.

To learn more about depression, visit the website for the National Institute of Mental Health (NIMH). For more information about vitamin D, check out the website for the Office of Dietary Supplements, a division of the National Institutes of Health (NIH).