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Vitamin D : What You Should Know

As I was wondering what to write for Wellness Wednesday (alliteration not intended, lol), I kept coming back to Vitamin D. This is actually very fitting, considering its role in immunity (think COVID-19), its role in cancer (did you know that February is National Cancer Awareness Month?), and that African Americans are especially vulnerable to Vitamin D deficiency (let’s talk Black History Month).

In a hurry? Skip to summary for the take home message.

What are some things you should know about vitamin D?

Where You Live Matters

Vitamin D is produced in the skin when it is exposed to sunlight. if you live above 37 degrees latitude, however, then you cannot receive enough sunlight (UVB) to help your body produce adequate amounts of Vitamin D. Imagine an invisible line under the cities of Richmond, VA, Denver, CO, and San Francisco, CA. If you live in or lateral to these cities and any points north, you are at greater risk for vitamin D deficiency (Guilliams, 2017).

What you eat matters

Top foods for vitamin D are fatty fish (e.g. sardines, salmon, mackerel), eggs, and beef (Guilliams, 2017). Other foods like dairy and orange juice are fortified with vitamin D, but it is always ideal to get vitamins from their natural resources.

The color of your skin matters

Dark skin (higher amounts of melanin) cannot optimally synthesize vitamin D from sunlight (Hart, 2020; Harris, 2014).

What about chronic disease and supplements?

Vitamin D can help prevent chronic disease

Vitamin D does so much more than give us healthy bones. Studies report that vitamin D can help prevent cancer (esp. colorectal, breast, and prostate), hypertension, and autoimmune disease (e.g. multiple sclerosis, rheumatoid arthritis, type 1 diabetes) (Wang et al., 2017).

There are very recent studies showing the importance of vitamin D in improving immunity, AND improving your outcome if you become infected with COVID-19. If you are a research geek like me and want to read these studies, let me know; I can send the links.

Why Supplemental Vitamin D? :

Everyone is on the vitamin kick these days. I personally believe that everyone should be taking vitamin D supplements, because most of us have low stores anyway. When is the last time you laid out in the sun with arms and legs exposed for at least 20 minutes? Plus, it’s winter time right now. Well, where I am anyway. Guidelines are changing (thankfully), and many authorities agree that 30 ng/ml is an optimal level of vitamin D in the blood (Guilliams, 2017). Ask your primary health care provider to test your vitamin D levels. It is a simple blood test called 25-hydroxyvitamin D, or 25(OH)D. Supplements are often referred to in units called IU’s. For optimal effects, key experts say we need to take at least 2,000 IUs per day (Guilliams, 2017).

For an extra tip, supplemental vitamin D in the form of D3 is the optimal, most bioavailable, form of vitamin D. It has been my experience that traditional practitioners will say there is no difference between D3 and D2. But on the contrary, studies show that supplemental vitamin D3 is 87% more potent than D2 (Guilliams, 2017)! So if it doesn’t matter to your PCP, then just go get you some vitamin D3!

Here's Another tip:

Many naturopathic providers say that a supplement of D3/K2 even trumps taking vitamin D3 alone, as they both function better together than alone (Nutritioninsight, 2020).

So, what can I say about vitamin D:

I have worked nights for 20+ years. Sometime around my 14-15 year mark, I found myself in the hospital getting a lumpectomy due to atypical hyperplasia--precancerous cells in my breast tissue. All I can say is thank the Lord he brought me through cancer-free. But when I look back, I see an interesting connection. I worked nights and hardly got any sunlight. I’m African American. I live north of the 37-degree latitude margin. I carried my cell phone in my left scrub pocket--the exact location of the site of atypical hyperplasia (environmental causes of cancer, a topic worth exploring). And finally a year later, my left leg appeared grossly more bowed than my right with ongoing left hip and knee problems and a diagnosis of left hip osteopenia. Does anyone else see a common denominator here?

I requested a vitamin D test from my PCP. Guess what my levels were? 6 ng/ml! Remember that anything under 30 ng/ml is suboptimal. Six is surely a deficiency.

NONE of my doctors made this connection. But I’m almost 100% sure that all these problems are somehow related to my low vitamin D stores.


  • Low vitamin D levels are related to chronic disease.

  • We are not getting enough sunlight and so will benefit from supplementation.

  • Due to pigmentation, African Americans cannot produce as much vitamin D from sunlight.

  • Ask your PCP for the vitamin D blood test.

  • Take vitamin D3!! With K2 if you can!!

*I am not a doctor. I cannot treat, advise, or diagnose. This information is for EDUCATION PURPOSES ONLY.

**See your doctor before starting ANY supplements!


Guilliams, T. G. (2017). Supplementing dietary nutrients: A guide for healthcare professionals. Stevens Point, WI:Point Institute

Hart, T. H. (2020, June 29). What Black People Need to Know About Vitamin D and Covid-19

Harris, S.S (2006, April 1). Vitamin D and African Americans. The Journal of Nutrition, Volume 136, Issue 4., April 2006, Pages 1126-1129.,

Nutritioninsight. (2020, May 19). The perfect pair: Vitamins K2 and D3 synergy shown to amplify effects of both.

Wang, H., Chen, W., Li, D., Yin, X., Xiaode, Z.,...Zheng, S. G. (2017, May 2). Vitamin D and chronic diseases. Aging Dis., 8(3): 346–353.


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