Between the extreme cold and the shortened daylight, people are more at risk of Vitamin D deficiency. Vitamin D is vital to bone health and helping our immune system function properly. This important vitamin reduces the risk of heart disease and diabetes, regulates mood and helps prevent colds and flu.
Good sources of Vitamin D are fatty fish such as wild salmon, eggs, mushrooms and fortified almond or coconut milk. Sunlight is the best source, but when we are stuck inside or bundled up in layers when outside it's a good idea to take a vitamin D supplement. 2000 to 4000 IU a day is the normal dosage although your doctor may recommend more.
Hope this help!
Dr. Matt Smith