This article is written by a student writer from the Spoon University at Northwestern chapter.

With winter approaching, each passing day is progressively darker and colder. If you didn’t already live in the library, it may suddenly feel like you never see the light of day. Unfortunately for us hard-working students, the absence of sunshine in your life probably also means a lack of Vitamin D in your system.

Vitamin D aids in the absorption of critical nutrients such as calcium, iron, phosphate, zinc and magnesium and can be obtained through food sources or synthesized by the body with direct exposure to sunlight. Normally most of the recommended daily dose of Vitamin D is covered through this exposure, but during periods of little daylight reliance on Vitamin D-rich foods are critical. Vitamin D deficiency has been linked to serious mental and physical health concerns, including depression, osteoporosis and other forms of bone damage, increased susceptibility to infections and greater risk of developing a variety of chronic and acute illnesses. So to keep your bones healthy and to fight the winter blues, you can supplement your diet with these 10 Vitamin D-rich foods:

1. Salmon

In addition to having one of the highest Vitamin D contents of any foods, salmon has many other health benefits. This versatile fish can be prepared in a variety of ways and makes an excellent accompaniment to this pesto pasta.

Photo by Ally Mark

2. Tuna

Fresh tuna can be expensive and intimidating to prepare, but the good news is that canned tuna works just as well. For a warm, hearty meal, try this 10 minute tuna casserole.

Photo by Ally Mark

3. Milk

Vitamin D is frequently added to milk and other commercial dairy products. Make sure to check the carton to see if it has been fortified with Vitamin D.