Vitamin D for Winter Immunity: How does it work?

Alison Pedler Alison Pedler
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happy woman soaking in winter sunlight

Did you know that your immunity can suffer when you get less sunshine in the winter? The days get shorter, the weather gets colder, and if we venture outside we’re all bundled up. Little sunshine exposure leads to reduced vitamin D levels, which has big implications for our health and disease resistance.

And as if winter itself wasn’t enough to limit our sunshine, many of us are still living, working and socializing at home as a result of the COVID-19 pandemic. That means we have that many fewer opportunities to spend a few minutes outside.

What role does Vitamin D play in our immune health?

adorable healthy little boy playing in the snow at sunset

Does vitamin D boost your immune system? The importance of vitamin D to immune health has been the focus of international research for some time.

Vitamin D is best known for regulating the amount of calcium and phosphate in our bodies. These nutrients are essential in keeping our bones, teeth and muscles healthy. A lack of the vitamin can cause bone diseases such as rickets in children and osteoporosis in adults.

However, the sunshine vitamin also has a proven connection to respiratory diseases. One study found that supplementing with vitamin D halved the cases of acute respiratory infection (cold and flu) among vitamin D-deficient people.

This year, the potential connection between vitamin D for immunity and COVID-19 has also been extensively studied. Early reports suggest there may be a correlation between vitamin D levels and symptom severity.

What are the symptoms of Vitamin D deficiency?

vitamin d deficiency headache fatigue nasal congestion

Many Americans have very low or deficient vitamin D levels, especially in the winter and spring, not knowing about vitamin D for winter immunity.

Symptoms of vitamin D deficiency include a weakened immune system, frequent infections and illness, fatigue, joint pain, and slow wound healing.

Because the signs of deficiency can be hard to see until illness has already begun, the best practice with vitamin D is to take proactive action and make sure your family is getting enough of it.

Good sources of Vitamin D

The obvious source of Vitamin D is sunlight: 15-30 mins of midday sun exposure a few times a week is enough to maintain healthy levels in the summertime, but in the winter this gets tricky. In northern latitudes, too little sunlight reaches the surface of the earth to be your sole source of vitamin D.

Another point to note is that if you live in a built-up area or a polluted environment where sunlight has difficulty penetrating to the ground, or if you have darker skin (higher levels of melanin make it harder for the skin to absorb sunlight), you face additional obstacles getting enough UV light. 

vitamin d rich foods fish parsley eggs dairy

Generally, the most consistent source of vitamin D for most people will be in their diets.

Very few foods contain Vitamin D naturally, but good sources include oily fish such as salmon, sardines, trout and mackerel. Red meats such as liver and beef also contain higher than normal levels. 

Another good alternative is to look for foods that are D-fortified, such as breakfast cereals, milk, yogurt and orange juice. Incorporating D-rich foods into your diet is typically enough to avoid deficiency, but may not be enough for optimal health.

Many physicians now recommend regular supplementation for their patients, especially in the winter months. There are many different supplements available, including chewable tablets, capsules, sprays and gummies. The recommended dose for adults is between 600IU and 5000IU per day. Take a supplement daily or weekly for full benefit. It’s best to get your levels tested to see what your personalized dosage should be.

Let a little sunshine into your life with this super little vitamin, and boost your immunity and overall health.

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