Benessere Clinic
Dr. Anthony Lowham

Vitamin D

“Live in the sunshine, swim in the sea, drink the wild air.” Ralph Waldo Emerson

I would like to provide some interesting information and a discussion on the benefits of sunlight, and the sunshine hormone that we call vitamin D.  Understanding the importance of adequate vitamin D and optimal immune health is necessary in regards to the current Pandemic resulting from COVID-19.

Few would argue against the benefit of fresh air and sunshine. At the same time, there remains a degree of anxiety in some people regarding the current situation and a perceived risk of exposure while traveling outside their residence.  Note that the recently instituted CDC guidelines are not new to 2020.  Banning public assembly, closing schools, isolating the infected and mandating the wearing of surgical masks were all instituted in many communities during the Spanish flu of 1917-1918.

During the Spanish flu, many temporary hospitals were constructed, just as they were during this current pandemic.  In many cases, these temporary hospitals were tent hospitals located outdoors. The above photo was taken at such a facility.  This outdoor hospital was comprised of twelve tents and was constructed after an outbreak of Spanish flu involving merchant sailors on training ships.  The number of seriously ill patients overwhelmed the local hospitals and this facility was constructed in less than a day.   In the one month that it remained open, 351 sailors were treated. The staff soon realized that taking the patients from their tents and placing them in the fresh air and sunlight was beneficial from both a physical and mental standpoint. (1,4)

Exposing sick patients to fresh air and sunlight wasn’t a new therapy.  “Open air” treatment of illness was primarily advocated for Tuberculosis, known at the time as ‘consumption’.  This description alluded to the weight loss experienced in patients. Although most patients with tuberculosis have latent disease and remain asymptomatic, a certain percentage with active disease required long term care. One early advocate of such treatment, George Bodington (1799–1882, was the proprietor of the first institution that could be described as a tuberculosis sanatorium near Birmingham, England.

He strongly argued that the practice of confining sufferers of ‘consumption’, “forcing them to breathe over and over again the same foul air contaminated with the diseased effluvia of their own persons” was unforgivable and a sign of apathy towards the afflicted.

He treated tuberculosis patients with a combination of fresh air, gentle exercise in the open and a nutritious, varied diet.  Make note, he not only advocated fresh air and sunshine, but exercise and good nutrition.  “For disease makes a slower progress when opposed by a firm muscular tone and good nutritive powers”. (2,4)

During World War I, the US and British Army frequently utilized “field hospitals” for the treatment or triage of wounded soldiers.  Military surgeon Lieutenant Colonel Sir Berkeley Moynihan observed in 1916, “In the treatment of all gunshot wounds where the septic processes are raging, and the temperature varies through several degrees, an immense advantage will accrue from placing patients out of doors. While in France I developed a great affection for the tented hospitals. There is great movement of air, warmth and comfort; when a sunny day comes the side of the tent may be lifted and the patient enjoys the advantage of open-air treatment.” (3)

What does being outdoors have to do with vitamin D?  The main source of vitamin D in our bodies depends on sunlight. Vitamin D is not required in the diet although it is present in fatty fish, liver, fish oils and egg yolk.  In many Northern climates, milk and other foods are fortified with vitamin D, although this is typically a variant known as ergocalciferol or vitamin D2 which may not be as effective.

The first step in the formation of vitamin D occurs in the skin as UVB rays convert 7-dehydrocholesterol to cholecalciferol.  Modification occurs first in the liver, producing 25-hydroxyvitamin D3 or Calcidiol.  Calcidiol then enters our circulation and is converted by the kidney and other tissues into the active form-1,25 dihydroxyvitamin D3 or Calcitriol.   One of the main functions of vitamin D3 is to increase intestinal Calcium, Phosphorous and Magnesium absorption from our food.  It acts to regulate proper bone mineralization and prevent osteoporosis. A severe deficiency of vitamin D, resulting in weak and soft bones, is known as “Rickets”.

But vitamin D3 has broad effects beyond its role in bone health. Calcitriol is also formed in other tissues including the brain and respiratory system.  Calcitriol produced in those tissues has localized effects, including immune system support. Vitamin D3 has receptors in every cell of our bodies.  It is actually not a vitamin, but a hormone.  Like other hormones, it has receptors within our cells and is able to bind to DNA and affect gene expression.  In this manner it effects the regulation of about 900 different genes.(5)

An analysis of multiple studies evolving vitamin D and respiratory infection demonstrated vitamin D supplementation was safe and protected against respiratory infection, especially in individuals who were the most vitamin D deficient. (6,7)

Significantly, two recent studies have demonstrated that patients with COVID-19 infection have worse outcomes if their vitamin D levels are low.

Vitamin D levels are expressed as ng/ml.   A level below 20 ng/ml is considered ‘deficient’ and levels  > 20ng/ml but <30ng/ml are considered ‘insufficent’.

A retrospective study from the Phillipines looked at 212 patients infected with COVID-19.
The overwhelming majority of patients with severe and critical COVID infection had vitamin D levels <30(insufficient) or <20 (deficient).

The study author concluded that Vitamin D supplementation could possibly improve clinical outcomes of patients infected with COVID-19. (8)

A second retrospective study, this one from Indonesia, examined the outcomes in 780 patients infected with COVID 19.  In this study, after correcting for age, sex and comorbid conditions, patients with insufficient (21-29ng/ml) Vitamin D levels had a mortality rate 7.6 times higher.   In patients with Vitamin D deficiency (<21ng/ml), the mortality rate was 10 times higher. (9)

Although these are retrospective studies, there appears to be a strong correlation between deficient and insufficient vitamin D levels and increased mortality from COVID 19 infection.  But understand, correlation does not necessarily mean causation. Elderly, frail, immunocompromised and metabolically unhealthy individuals tend to be less physically active and spend less time outdoors.  As a result, they have lower levels of Vitamin D.

Increasing vitamin D levels, especially in susceptible populations requires simple, effective measures. According to a 2011 study, over 40% of adults in the US are deficient in Vitamin D (<20ng/ml).  This is even higher in populations with increased skin pigmentation including Native Americans, Hispanics and African-Americans. (10)

How to Raise Vitamin D

  1. Regular sun exposure is the most natural way to raise vitamin D levels. Aim for 10–30 minutes of midday sunlight, several times per week, without sunscreen. People with pigmented skin may need a little more than this. Your exposure time should depend on how sensitive your skin is to sunlight.
  2. Eat whole, nutrient dense foods and avoid processed food. Remember, Vitamin D is primarily supplied by sunlight, not food. But our physiological state including obesity and metabolic syndrome is related to low Vitamin D levels. I will be posting an article in the near future with nutritional and dietary guidelines for improving metabolic health.
  3. Vitamin D supplementation. To best guide recommendations for supplementation, it may be reasonable to obtain a blood test to determine your vitamin D3 level.   Typically, in vitamin D3 deficient patients, I utilize 10,000iu/daily for 1-3 months and then switch to 5,000iu/daily.
    In my opinion, vitamin D3 (cholecalciferol) is recommended over vitamin D2 (ergocalciferol).  Vitamin D3 (cholecalciferol) is formed primarily from sunlight exposure and is present in small amounts in dietary animal products (Fish).  Vitamin D3 (cholecalciferol) is more effective at improving vitamin D status. Vitamin D2 (ergocalciferol) is plant derived from UV exposure (mushrooms grown in UV light, yeast exposed to UV light) and is most commonly used to fortify foods because it is cheaper.
    There are a couple of other important considerations. First, understand that Vitamins/Supplements/Nutraceuticals are not regulated by the FDA.  You need to ensure you are obtaining  products from a reputable company.  Second, in my opinion, any vitamin D3 supplement should contain vitamin K2 or Menaquinone.  As discussed, vitamin D3 assists in Calcium absorption, vitamin K2 is necessary to ensure Calcium deposition in bone.
  4. If you are interested in increasing your Vitamin D3 level primarily for improved immune health, other supplementation may be beneficial.This is a list of the supplements I am currently taking for immune health.  In my opinion, these supplements have research proven benefits to improve immune health.

A. Vitamin D3 with K2, 5,000iu/daily
B. Liposomal Vitamin C 1,000mg twice daily
C. Zinc picolinate 30mg twice daily
D. Zinc lozenge (Cold Eeze) prior to anticipated close contact.

If you have any questions, please email me at or call Benessere Clinic (332-6222)

Anthony Lowham MD


  1. Anon Influenza at the Camp Brooks Open Air Hospital. JAMA. 1918;71:1746–1747. [Google Scholar]

  2. Bodington G. An Essay on the Treatment and Cure of Pulmonary Consumption, On Principles Natural, Rational and Successful. London, England: Simpkin, Marshall, Hamilton and Kent; 1906. [Google Scholar]
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  5. Bivona G, Agnello L, Ciaccio M. The immunological implication of the new vitamin D metabolism. Cent Eur J Immunol. 2018;43(3):331‐ doi:10.5114/ceji.2018.80053
  6. Martineau AR, Jolliffe DA, Hooper RL, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. 2017 Feb 15;356:i6583.
  7. “Vitamin D Fact Sheet for Health Professionals”. National Institutes of Health (NIH). February 11, 2016
  8. Alipio, Mark, Vitamin D Supplementation Could Possibly Improve Clinical Outcomes of Patients Infected with Coronavirus-2019 (COVID-19) (April 9, 2020). Available at SSRN: or
  9. Raharusun, Prabowo and Priambada, Sadiah and Budiarti, Cahni and Agung, Erdie and Budi, Cipta, Patterns of COVID-19 Mortality and Vitamin D: An Indonesian Study (April 26, 2020). Available at SSRN: or
  10. Forrest KY1, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutr Res. 2011 Jan;31(1):48-54. doi: 10.1016/j.nutres.2010.12.001.