We shall welcome them on the beaches.
We shall welcome them on landing grounds.
We shall welcome them in the felds and in the streets.
We shall welcome in the hills.
Lydia Towsey
In the early 20th century, children in the United Kingdom were experiencing high incidents of a developmental disorder. Rickets, a condition affecting bone growth and strength, was so prevalent it came to be known as “the English Disease.”
The King’s College for Women in London, which happened to have male faculty, tasked biochemist and nutritionist Edward Mellanby with figuring out the cause and potential cure for this disease.
In his experiments, Mellanby decided to feed dogs a diet of oatmeal — one which matched that of the Scottish people — who happened to have the highest incidents of rickets in the U.K. As expected, the dogs developed rickets. To cure them, Mellanby used cod liver oil, and sure enough, it worked. But what was it in the oil specifically that healed this disease?
Another professor, Elmer McCollum of Johns Hopkins, would figure that out.
Some in the academic community believed it was vitamin A within the cod liver oil which cured rickets. By oxidizing the cod liver oil, effectively destroying the vitamin A, McCollum tested whether the preparation would work. When it did, he correctly concluded the substance within cod liver oil curing rickets was a new vitamin altogether; he and his colleagues named it vitamin D.
Interestingly enough, coinciding with the discoveries of McCollum and Mellanby, a physician in Vienna named Huldshinsky, along with Chick and colleagues from England, found that children suffering from rickets could be cured by exposure to summer sunlight or artificially produced UV light.
A fuller understanding of the structure and function of vitamin D would come courtesy of a study from Askew et al., 15 years later. Based on these findings, in the 1930s, vitamin D was added to milk, a drink routinely consumed by children, in an effort to eradicate rickets.
What’s in a name?
Vitamin D isn’t really a vitamin at all, it’s a hormone. Cholecalciferol — commonly called vitamin D — is a steroid hormone, synthesized via UVB exposure from 7-dehydrocholesterol, a type of cholesterol universally present in the skin. Vitamin D can also come from dietary sources, through supplements or fortified foods, like milk.
Vitamin D is critical for calcium absorption, reduction of inflammation and regulating cell growth, neurological, muscular, and immune function, as well as glucose metabolism. These dual roles in inflammation and immune function likely led clinicians and academics to, once again, look into vitamin D levels in another disease, Covid-19.
Leading the charge was the University of Chicago and David Meltzer, MD, PhD. Data from the University of Chicago Medical Center provided some of the earliest evidence to support the hypothesis that vitamin D deficiency may affect Covid-19 risk. Patients with untreated vitamin D deficiency were 77% more likely to test positive for Covid-19 than patients who were not likely deficient.
In an effort to shed more light on this issue, a clinical trial involving 2,700 men and women is underway, and set to conclude on December 31, 2021.
The Vitamin D and Covid-19 Trial (VIVID) — sponsored by Brigham and Women’s Hospital, in collaboration with Harvard Medical School and Harvard School of Public Health — is a nationwide randomized clinical trial to investigate whether taking a daily dietary supplement of vitamin D for four weeks reduces disease severity in participants newly diagnosed with Covid-19, and reduces the risk of infection in household contacts of someone newly diagnosed.
Ver:
The vitamin D for COVID-19 (VIVID) trial: A pragmatic cluster-randomized design
A dose of D
Physicians aren’t waiting for the VIVID trial to conclude, however; according to SingleCare.com, prescription strength vitamin D (50,000 IUs) was second only to amoxicillin as the most prescribed “drug” of 2020. Bear in mind, NIH guidelines for vitamin D intake range from 400 IUs for children to 800 IUs for seniors. Those considering higher doses should speak to their physician prior to supplementing in order to avoid toxicity.
For those curious whether they have adequate levels, a simple blood test can check your serum vitamin D, also called 25-hydroxyvitamin D. Anything below 20 ng/mL is considered deficient; concentrations up to 50 ng/mL are normal. Should you find yourself lacking in vitamin D, dietary changes, supplements, or approximately 15 minutes of sun exposure can increase levels to a normal range.
Vitamin D does seem to be a rare area of agreement among vaccine advocates and those less likely to claim vaccines are a panacea. Frequent podcast guests and cable news fixtures, including evolutionary biologist Bret Weinstein, PhD, internist Meltzer, and Anthony Fauci, MD of the NIH, have all argued in favor of supplementation (for those deficient) to maintain healthy levels of vitamin D.
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