(WHTM) — Many of us have limited time outdoors in the winter, which means that many of us aren’t getting enough vitamin D. How can that impact our health?

“Vitamin D is really essential, especially when we’re talking about bone density. It works really well with calcium. A lot of times what happens is, if we’re not getting enough calcium in our diets, the body actually will decrease the calcium stores. So vitamin D kind of helps maintain those calcium stores to keep our bones nice and strong. A lot of research actually does support that vitamin D helps with overall mood,” stated registered dietitian Beth Czerwony of the Cleveland Clinic.

Czerwony explained that many people who have a vitamin D deficiency can find out with simple blood tests. However, some warning signs can include fatigue, bone pain, muscle weakness, and mood changes.

Simple food changes like fatty fish, salmon, tuna, mackerel, and sardines are all good food options to help with vitamin D. deficiency. Mushrooms, egg yolks, and milk are also fortified with vitamin D.

Czerwony also encourages people to talk with their doctor to see if a vitamin D supplement is necessary. If it is, the time of day that you take it can make a difference.

“I always recommend eating it with your heaviest meal because it is a fat-soluble vitamin. It’ll actually increase your absorption better with some sort of fat, and so typically people take it in the morning because it’s kind of – we usually end up taking our vitamins in the morning. But a lot of times, our breakfasts aren’t very heavy – they’re pretty light. So I always recommend doing it at your evening meal if that’s your biggest meal, and you’ll actually end up seeing the numbers increase a little bit faster,” said Czerwony.

Your doctor may want to check your vitamin D levels regularly if you have certain risk factors for a deficiency.