Nutrient Spotlight: Vitamin D

Nutrient Spotlight: Vitamin D

Vitamin D is a known immunity system supporter that delivers similar sunshine-y goodness that comes from the sun. There are serious risks of Vitamin D deficiency on your health and immune system, accelerating the aging process. Risk for cold and flu has been shown to be higher in people who aren’t getting adequate Vitamin D from the sun or in their diet. In fact, data pooled from 25 studies with over 10,000 participants found that those who supplemented with Vitamin D, had a 10% lower risk of infection and for those with a diagnosed D deficiency, their risk after supplementation was cut in half.1,2     


Why is Vitamin D so important?

In addition to immune support, Vitamin D helps protect us in many ways. We have receptors for Vitamin D all over our body, allowing it to influence our cardiovascular, endocrine (hormone) and nervous systems.3  Vitamin D is known as a fat-soluble vitamin, that functions as a hormone in our body, playing a vital role in processes like stopping the vulnerability or degradation of our DNA as we age.


Some Specific and Surprising Roles Vitamin D Plays is Helping Our Bodies Protect Against:


Poor bone health, increased risk for falls and imbalance, especially with age and rickets in the very young, occur with inadequate Vitamin D.

We all know we need D for our bones, but do you know why? We need Vitamin D to help absorb calcium in our gut and to regulate the availability of bone building minerals calcium and phosphate, in our blood.17


Low levels of Vitamin D may increase a persons’ risk for certain cancers, like colon cancer. One large study found that after 5.5 years, persons with healthy Vitamin D blood levels had a 22% lower risk of developing colorectal cancer17,18 The relationship between Vitamin D status and other various cancer risks continues to emerge as more research is conducted.

Heart Disease, High Blood Pressure3

Low levels of Vitamin D have been associated with increased risk for heart attack and stroke.  However, the American Heart Association notes that the amount of D suggested for bone health should be sufficient for promoting a healthy heart. More isn’t always better as excess levels of Vitamin D could contribute to calcification of arteries in some individuals.19 

Mood Disorders/Depression/Anxiety5,21

Sunshine and happiness sure go hand in hand! It’s no wonder that Vitamin D has been studied for its role in helping to ease symptoms associated with depression and other mood disorders. Seasonal Affective Disorder, or SAD, which is often remedied with light therapy, encourages the body to convert the UV light into Vitamin D.  Some studies found supplemental D even more effective than light therapy for SAD. Recent studies examining depression that provided higher doses of D (2,000 IU vs. 400-600 IU) in persons who are overweight or obese and therefore at greater risk of deficiency, have found more significant improvements than earlier research using lower doses in persons without a deficiency.22  

Cognitive Decline4,23,24

Vitamin D is critical for our body to communicate effectively; it influences the growth and protection of our cells, including nerve cells, plus it can downshift inflammation that inhibits cell communication.  We have receptors for Vitamin D in areas of our brain that are responsible for cognitive functioning, like the hippocampus and human cortex.  Studies show that 70-90% of elderly persons diagnosed with Alzheimer’s disease are deficient in Vitamin D.

Risk for Cold/Flu and More Severe Symptoms of Infection1,26,27,28

Persons with higher blood levels of Vitamin D within the healthy range, have been shown to have significantly lower risks of respiratory infections. A global meta-analysis of 25 studies with over 11,000 people found that Vitamin D plays a critical role in helping our body fight acute respiratory infections.

You can read more about Vitamin D & Immunity in our blog post “How to Support Your Immune System During a Pandemic (and Beyond)”.


An estimated 79 million people in the US have pre-diabetes and nearly 285 million have been diagnosed with diabetes worldwide, mostly type 2. Vitamin D can help our body be more sensitive to, or less resistant to insulin, the hormone we need to move glucose (sugar) from our blood into our cells so they can use it for energy. Some studies suggest Vitamin D helps our pancreas to make and secrete or release more insulin. Further investigation into how Vitamin D reduces risk for pre-diabetes and type 2 diabetes is underway.

Autoimmune Conditions (MS)

Healthy levels of Vitamin D were associated with a significantly lower risk for developing multiple sclerosis, especially in younger persons with lighter skin.20,21


What are known risk factors for Vitamin D deficiency?

Research has shown that as much as 40% of the US adult population is Vitamin D deficient. There are many factors that impact Vitamin D deficiency, including:

  • Age
  • Skin Color and Melanin
  • Geography
  • Malabsorptive Gut Disorders
  • Obesity
  • Occupational Hazards

Read more about these risk factors in our blog post “The Vitamin D Disparity”.

Where do we get Vitamin D? 5,17

  • Sunshine: We mostly get our Vitamin D from the sun. Just 15 minutes of sunshine (without sunscreen) per day is enough, in a healthy person, for the body to use the UV light to activate Vitamin D in the body. But remember to wear sunscreen the rest of the time to reduce risk of melanoma and other skin cancers.
  • Food: Obtaining enough Vitamin D through your diet is a far less efficient way of obtaining enough for supporting your health, compared with sun exposure or supplements. While these foods also have other nutrients important for our wellbeing, like protein, Vitamin E, calcium and potassium, the Vitamin D we consume from them must first be absorbed and then activated.
    • Fatty fish like sardines, salmon, herring, mackerel
    • Egg yolks
    • Milk, cheese, yogurt and other dairy products
    • Fortified nondairy milks, yogurts, juices, cereals and other packaged food products
    • Mushrooms
    • Supplements: Vitamin D is a great example of a nutrient to consider supplementing since it can be difficult to get enough of it from food and sun alone. We need at least 600-800 IU per day, however, more is often needed to sustain an adequate blood level, based on individual risk factors. For people at risk or deficient in Vitamin D, the recommended range is typically 1,000-4,000 IUs per day (or 25 mcg – 100 mcg), but discuss with your doctor before starting any supplement program.



    26. Vitamin D for prevention of respiratory tract infections: A systematic review and meta-analysis. Charan J, Goyal JP, Saxena D, Yadav P. J Pharmacol Pharmacother. 2012 Oct; 3(4):300-3.


    About Stacy Kennedy

    Photo by Valeria Boltneva from Pexels

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