Research is emerging connecting higher blood levels of Vitamin D with improved immunity to fight infections and cancers. However, most people are seriously deficient and unaware of the danger to their health. Few healthcare providers measure it, let alone treat it.

Why is Vitamin D so important?

Vitamin D is needed to absorb calcium and promote cellular functions. Every immunity cell in the body needs Vitamin D to activate thousands of specific genes to fight infections, inflammation and destroy abnormal cells. If someone has a low amount of Vitamin D, immunity will be greatly reduced. Studies have shown that higher D levels prevent heart disease, reduce cancer risk, improve blood pressure and diabetes. A blood test will help you identify if you’re dangerously low. Anecdotally, I’ve heard doctors say that it isn’t Cold/Flu Season that brings on illness but rather low Vitamin D Season.

Early in the Pandemic, Israeli researchers examined the Vitamin D levels of 1,400 participants who took a COVID-19 test from February 2020 to April of 2020 (before COVID-19 vaccines).

· Only 10% tested positive for COVID-19 if their Vitamin D level was above 30 ng/ml.

· However, if the Vitamin D level was below 30 ng/ml, nearly 90% tested positive for COVID-19.

· Adults with an average age of 50 were also more likely to be hospitalized with a COVID-19 complication if their Vitamin D levels were below 30 ng/ml.

 What impacts Vitamin D levels?

Sunlight, oily fish, some fortified foods and supplements increase Vitamin D levels but most of us don’t get enough. It’s challenging because too much sun increases risk for skin cancers. Darker skinned people are at greater risk for Vitamin D deficiency due to higher levels of melanin in their skin which blocks the sun. People living in northern climates or use high levels of sunblock are also at greater risk. Supplements are needed to raise levels to protect against infections and cancers.

How does the body produce Vitamin D?

Sunlight absorbed through the skin and foods turns into cholecalciferol which goes to the liver. Vitamin D3 supplements are in the form of cholecalciferol. It’s a slow process that takes approximately 21 days for the liver to change cholecalciferol into 25(OH) D calcifediol, the form needed by the immune cells. Calcifediol is then stored in the blood. It is this form of Vitamin D that is measured by a blood test. Thus, once you increase your Vitamin D intake, it will take 3 weeks before it’s ready to be used.

When an infection, illness or abnormal cell develops, the immune cells use some of the stored calcifediol to make a fast-acting form of Vitamin D called calcitriol. It only takes 2 hours to change the stored calcifediol into calcitriol. The T lymphocyte fighter white blood cells use this form to activate 11,000 genes that destroy infections, and abnormal cells. If your Vitamin D levels are low, you will not have enough for the fighter cells to do their job. Infections and cancers worsen.

A small study in Spain found immediate benefits from administering the fast acting (2 hour) calcitriol form of vitamin D to ill patients hospitalized with COVID-19 Pneumonia. While a study done in Brazil gave the slow acting supplement cholecalciferol to ICU patients which showed no benefit. Their results are not surprising since slow acting cholecalciferol would take 3 weeks for the liver to convert it to a form the cells could use. Sick patients need Vitamin D immediately. The faster acting form calcitriol probably would have shown a huge benefit but wasn’t given.

Interestingly, calcitriol is not available throughout the world. One has to wonder why studies haven’t been done and why this faster acting safe effective supplement isn’t available everywhere for sick patients. The bottom line for now is to increase your Vitamin D3 cholecalciferol (slower form now available) weeks before you think you might need it or remain on it all year long.

What does the lab value of Vitamin D mean?

Quest Diagnostic Values

Optimal                      30 ng/ml to 100 ng/ml

Low optimal               20 ng/ml to 29 ng/ml

Low deficiency           less than 20 ng/ml

While guidelines vary, increasingly, most recognize that anything below 30 is deficient and unsafe. Many recommend reaching a level above 40.

How much should you take?

As a nurse I’m not at liberty to tell you how much Vitamin D3 (cholecalciferol) you should take, since I don’t know anything about you or your medical history. It’s best to begin with a Vitamin D blood test and follow your healthcare provider’s advice. My husband and I take 4,000 IU’s a day with 100 mcg of K2 (MK-7) to keep our D levels around 40.

Vitamin D plays a major role in regulating blood calcium levels. When it’s too low, Vitamin D will pull calcium out of the bones needed for body processes. Higher doses of Vitamin D can cause too much calcium to circulate in the blood. K2(MK-7) is a vitamin that helps to keep calcium in the bones when taking Vitamin D supplements.

It’s always important to check with your provider, especially if you’re taking blood thinners! Vitamin K makes the blood clot more easily. Supplements of any kind may NOT be appropriate for some people.

Speak with your provider about the appropriate dose of D3 for an infant, toddler, older child, adult, senior, obese patient, people with mal-absorption syndrome and anyone taking medications. Specific guidelines are not available for pregnant and breastfeeding women.

What are the side effects from Vitamin D?

Most people tolerate Vitamin D3 supplements very well but it’s important to get your blood level checked and work with you provider. Some side effects may be:

· Increased calcium blood levels

· Nausea and vomiting

· Constipation

· Weakness

· Confusion

· Kidney stones

On a personal note:

Recently, a friend saw her healthcare provider who diagnosed her with osteopenia, a disease that leads to brittle bones that may fracture easily. Her Vitamin D level was in the 20’s and was told to take 2,000 units of Vitamin D each day. I was shocked at this prescription. The level is probably too low for her problem and most likely requires a much higher dose. I encouraged her to get a second opinion with a provider who is more current on the treatment for osteopenia. She agreed. My advice to you is learn more about Vitamin D deficiency. Get your level tested and ask your provider how much you need to raise it to safe levels.

Gracious words are like a honeycomb, sweetness to the soul and health to the body.

(Proverbs 16:24).

References:

Ghelani, D,  Alesia, S. & Mousa, A. “Vitamin D and COVID-19: An Overview of Recent Evidence,” Pubmed, September 29, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8509048/

“Vitamin D,” Mayo Clinic, August 10, 2023. https://www.mayoclinic.org/drugs-supplements-vitamin-d/art-20363792

Merzon, et al., “Low Plasma 25(OH) Vitamin D Level Is Associated with Increased Risk of COVID-19 Infection: An Israeli Population Based Study,” The FEBS Journal, July 23, 2020. https://doi.org/10.1111/febs.15495

Elamir, Y. M et al. “A Randomized Pilot Study Using Calcitriol in Hospitalized Patients,” Pubmed, January 2022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8425676/

Murai I.H. et al. “Effect of a Single High Dose of Vitamin D3 on Hospital Length of Stay in Patients With Moderate to Severe COVID-19: A Randomized Clinical Trial.” JAMA. 2021;325:1053–1060. https://pubmed.ncbi.nlm.nih.gov/33595634/

“Vitamin D Numbers What the Really Mean,” Quest Diagnostics,2024. https://www.questdiagnostics.com/healthcare-professionals/about-our-tests/endocrine-disorders/vitamin-d-numbers    

Daniel A. “Meet Vitamin D3 + K2: The Potent Pairing of Essential Vitamins You Need Daily” BrainMD, May 15, 2023. https://brainmd.com/blog/benefits-of-vitamin-d3-k2/