11vitamin D

Beat Cold & Flu and the Winter Blues with ONE Crucial Nutrient

Each year, the winter solstice falls on December 21, a day that’s categorized by the shortest period of daylight and longest stretch of night. As hours of daylight decrease from the summer solstice on June 21, the body’s biological clock, otherwise known as our circadian rhythm, shifts. Even the slightest change to this internal rhythm can cause disruptions in sleep and wake patterns, hormones, mood, energy and motivation.


  • Seasonal Affective Disorder (SAD) is a form of depression that occurs in the fall or winter months, likely due to fewer hours of daylight. It affects approximately 20% of people in the United States.
  • Symptoms of SAD include fatigue, irritability, increased carb cravings, weight gain, withdrawal and loss of interest.
  • Up to 85% of Americans are deficient in vitamin D, a nutrient that is linked to SAD.
  • Vitamin D helps boosts the immune system, fight cancer, ease autoimmune conditions, regulate blood sugar, strengthen the bones, balance hormones and lift mood.
  • Book a consultation with our Nutritionist to find out the best vitamin D-rich real foods, as well as other ways to naturally beat the winter blues, and fight the winter cold & flu!

If you find yourself fatigued, irritable, craving carbs, gaining weight, withdrawing from social activity and losing interest in normal hobbies around this time of the year, Seasonal Affective Disorder (SAD) may be the culprit! According to Integrative M.D. Andrew Weil, up to 20% of people in the United States are believed to suffer from SAD, a form of depression that occurs in the fall and winter, likely in response to fewer daylight hours.

Often referred to as the “doctor in the sky,” the sun is responsible for more than simply warming the earth and tanning the skin. One of its most important roles is to provide vitamin D, an essential fat-soluble nutrient that the body produces in response to sun exposure. Vitamin D acts more like a hormone than vitamin, helping to maintain balance (homeostasis) in the body. In addition, vitamin D is required for calcium absorption – the two nutrients work in synergy to grow and strengthen the bones, maintain heart function, assist in muscle contractions and improve nerve function.


Vitamin D also plays an important role in immunity. It helps prevent inflammation, diabetes, autoimmunity and even cancer. Vitamin D’s immune-boosting properties protect against colds, flu and infection. In fact, as cited in an article by Dr. Joseph Mercola, studies across multiple countries concluded that when an individual is deficient in vitamin D, supplementation is 10 times more effective than the flu vaccine!

Furthermore, every tissue in the body, including the brain, has receptors for vitamin D. This nutrient aids in the release of “feel good” brain chemicals dopamine and serotonin, which improve mood while calming stress and anxiety. Vitamin D also positively affects blood sugar balance, estrogen levels and quality of sleep. From neurochemistry to genetic expression and hormonal balance, vitamin D is a key player in mood, cognition, memory and overall balance within the body.

Yet with such a significant role in health and vitality, according to the Vitamin D Council, 70% of the U.S. population isn’t meeting the estimated average requirement of vitamin D. As access to the sun’s concentrated dose of vitamin D becomes more limited, a focus on nutrition becomes key to fending off SAD. From late fall to early spring, bolster your diet with vitamin D-rich foods and/or supplements. Wild-caught salmon, pasture-raised egg yolks and cremini mushrooms are good food sources; however, they typically don’t provide enough vitamin D to correct moderate to severe insufficiencies. Depending on your vitamin D levels, supplementation may be necessary.

pasture-raised egg yolk

But take note: vitamin D is a fat-soluble nutrient with the ability to build up in the tissues and cause toxicity if overdone. Before supplementing, be sure to check your vitamin D levels by requesting a 25-OH vitamin D3 test during routine blood work. If the resulting value falls under 50 ng/mL, supplementation may be beneficial. Consult with your healthcare practitioner or nutritionist for a recommendation based on your current levels, dietary intake and health status.

From immunity and bone strength to mood, energy and disease prevention, vitamin D plays an undeniable role in total body health. If you resonate with any of the symptoms of SAD – fatigue, weight gain, depression, withdrawal, etc. – consider getting your vitamin D levels checked. This deficiency could be the missing link to correcting your seasonal slump, and a simple correction with food or supplementation can help tremendously! Call 630.You.Well  (630.968.9355) to book a consultation with our Nutritionist to find out the best vitamin D-rich real foods, as well as other ways to naturally beat the winter blues, and fight the winter cold and flu!

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