It's true - winter blues really do exist!

Washington, Dec 21 (ANI): Do you feel low during winters or are you the kind who hates summers? Turns out, weather affects our moods more than we think.

Researchers at Humboldt University in Berlin studied more than 2,000 Germans and found that people can be categorised in four basic ways - those people who are unaffected by the weather or seasons, people who love summer, people who hate summer and people who love rain.

They also found that children tend to be the same types as their mothers but don't know if the categories have any genetic basis or are learned.

One underlying cause of some season and weather-related depression could be vitamin D deficiency.

"There is a seasonal variation and that's well documented," Discovery News quoted Sue Penckofer, a professor at Loyola University Chicago, as saying.

Those symptoms, which include fatigue, can be helped with a little more vitamin D (although not too much, since vitamin D is toxic in large quantities).

Vitamin D deficiencies are not uncommon in the winters, Penckofer explained, especially among darker skinned individuals.

"What I can say for a fact is that we have seen people reporting that they feel better and don't feel as tired" when they are supplementing their vitamin D," Penckofer said.

"One lady said 'I feel like the Energizer bunny.'"

Although vitamin D is not the only reason, it another factor to consider in the ongoing battle to sort out how weather affects us.

The study is published in the journal Emotion. (ANI)