Journal of Infectious Diseases & Therapy
Open Access

The term "vitamin D" refers to a class of fat-soluble secosteroids that promotes the intestinal absorbance of calcium, iron, magnesium, phosphate, and zinc. The two most significant of these substances in the human body are vitamin D3 and vitamin D2 [1,2]. Unlike Vitamin D2, which is primarily derived through diet, Vitamin D3 is naturally produced by the skin on exposure to UV radiation. The liver is where vitamin D is transferred and converted to 25-hydroxyvitamin D. The 25-hydroxyvitamin D blood test is used in medicine to measure the body's vitamin D levels. The most accurate measure of vitamin D status is considered to be the blood level of 25-hydroxyvitamin D (containing D2 and D3). According to limited studies, vitamin D supplementation helped some hospitalized patients experience lower COVID-19 symptoms. Today, vitamin D deficient is viewed as a worldwide epidemic [3]. The majority of human body cells have vitamin D receptors, which means that for them to function properly, vitamin D levels must be adequate. Many of them previously believed, vitamin D deficiency poses serious health hazards. Osteoporosis, osteochondrosis, multiple sclerosis, cardiovascular disease, complications during pregnancy, diabetes, depression, stroke, autoimmune diseases, influenza, cancer, infectious diseases, Alzheimer's disease, obesity, and high mortality are just a few of the serious diseases that are linked to vitamin deficiency [4]. Therefore, testing (25-OH) vitamin D levels is now considered a "medically necessary screening test" and maintaining adequate levels may improve not only bone health but overall health and well-being. [5] Vitamin D deficiency reduces the immune system activity in every individuals including the individuals effected with SARS-CoV.

The sunlight exposure and Vitamin D3

Since more than 500 million years ago, the planet has created vitamin D, a vitamin that is produced in sunlight. When exposed to sunlight, the skin's 7-dehydrocholesterol absorbs UVB rays and transforms into previtamin D3, which then isomerizes to vitamin D3. In addition to absorbing UVB rays, previtamin D3 and vitamin D3 are also transformed into a range of photoproducts, some of which have particular biological characteristics. Season, time of day, latitude, altitudes, air pollution, skin pigmentation, sunscreen usage, walking on glass and plastic, and ageing all have a significant impact on sunlight-induced vitamin D production [1]. Exposure to sun in the early hours of the day improves the body activity in COVID-19 individuals reducing the respiratory distress.

Different effects of vitamin D2 and D3 on the immune system

According to a recent study, vitamin D2 and D3 supplements showed differing impacts on immune system-related genes [6]. These results are important because the majority of earlier research has been unable to establish a clear distinction between the effects of vitamin D2 or D3 treatment.

The majority of studies that have been released to date have demonstrated that the impact on circulating vitamin D levels is the primary distinction between vitamin D2 and D3 administration. Studies have evidenced that vitamin D3 is superior at increasing the body's vitamin D levels. A recent analysis of the available data indicated that vitamin D3 administration increased vitamin D levels in the body more effectively than vitamin D2 administration. Not all studies, meanwhile, support this theory.

Few research studies states that vitamin D2 supplementation is more preferable than vitamin D3 supplementation. In a study, vitamin D2 performed better in treating immunological issues in people receiving steroid therapy. Apart from raising vitamin D levels in the body, there isn't much proof that vitamin D3 pills are superior to vitamin D2 supplements. According to study, vitamin D3 increased calcium levels more effectively when compared to vitamin D2.

Test method for Vitamin D status

Vitamin D is quickly transformed to 25(OH)D when it is ingested or produced mostly by skin, but only a small portion of 25(OH)D is converted to 1,25(OH)2D in serum. As a result, measuring total 25(OH)D levels is a reliable test to determine the body's vitamin D stores. Vitamin D deficiency can be identified and tracked using total 25(OH)D levels, while treatment monitoring can be facilitated by quantitative 25(OH)D2 and 25(OH)D3 levels.

An absence of an increase in the corresponding 25(OH)D2 or 25(OH)D3 and total 25(OH)D levels, for particular, in patients who have not noticed clinical improvement after taking D2 or D3 supplements, may indicate inadequate dose, nonadherence, or malabsorption.

In individuals with healthy kidneys and bones, normal serum calcium and phosphorus levels are maintained primarily through the interaction of two hormones: Parathyroid Hormone (PTH) and ossified triol. In COVID-19 patients with vitamin D deficiency, secondary HPT causes the release of calcium that has been stored in the bones and causes the kidneys to reabsorb calcium to ensure normal serum calcium and phosphorus levels.

Vitamin D deficiency in COVID-19 individuals is usually accompanied by normal blood calcium and phosphorus levels, high normal or elevated levels of parathyroid hormone, normal to elevated levels of total alkaline phosphatase, low 24-hour urinary calcium excretion rates, and low levels of total 25(OH)D. Although this is the rare, patients with severe chronic vitamin D deficiency may experience considerable hypophosphatemia and/or hypocalcemia. By evaluating 1,25(OH)2D levels, doctors shouldn't be able to identify vitamin D deficiency. As a result, patients with vitamin D deficiency who have elevated levels of metanephrine may have their vitamin D status misinterpreted. Osteotriol levels are typically normal or even elevated in these patients.

Evaluation of Fiatest vitamin D test cassette (serum/plasma)

Principle of the Test: The Vitamin D Test Cassette (Serum/ Plasma) is based on a fluorescent immunoassay for the detection of vitamin D. The specimen sample moves from the sample pad to the absorbent pad. The vitamin D in the sample is competing with the VD-BSA antigen on the envelope. Less vitamin D is available in the sample the more fluorescent microspheres coupled to the anti-vd antibody are captured by the VD-BSA antigen encapsulated on the membrane (Test line). The concentration of vitamin D in the sample is inversely associated with the strength of the fluorescence signal captured on the T-line. Based on the test's fluorescence intensity and the standard curve, the fluorescence immunoassay analyzer may compute the sample's vitamin D concentration.

Materials and directions for use: Materials provided included a test cassette, specimen collection tubes with buffer, ID card, and a package insert. To complete this test, additional materials are required but not provided. They include a timer, centrifuge, a fluorescence immunoassay analyzer, pipettes and specimen collection containers. Prior to testing, can let test, specimen, buffer, and/or controls get to room temperature (15 ˚C-30 ˚C).

Before beginning the test, turn on the adapter's fluorescence immunoassay analyzer's power source. Select the test mode and specimen after taking out the ID card and inserting it into the appropriate slot. The test cassette should then be taken out of the foil pouch and used within an hour. The assay should be carried out as soon as the foil packet is opened for the most accurate results.

Pipette 25 µl of serum or plasma into the buffer tube while the test cassette is horizontal and spotless. After mixing the specimen and buffer thoroughly for 2-5 minutes, use a pipette to pour 75 µl of the diluted sample into the sample wells of the test card. Turn on the timer and the test results should be read by the fluorescence immunoassay analyzer after 15 minutes (Table 1). Each laboratory should determine the applicability of the reference range through experiments and establish its own reference value range if necessary to ensure that it can correctly reflect the situation of a particular population as vitamin D intake varies by region, age group and skin color [7,8].

Table 1: Expected results.

At Vitamin D is important for bone and non-bone health. It is now well established that many people have vitamin D levels that are below the currently recommended optimal health levels. Worldwide, vitamin D is obtained primarily through exposure of patients with COVID-19 to UVB radiation and skin production of vitamin D from sunlight. Latitude, cultural dress habits, seasons, sun protection and sun exposure may all limit vitamin D production. The Fiatest Vitamin D Test Cassette uses a fluorescence immunoassay with an adapted fluorescence immunoassay analyzer to determine vitamin D level in the human body by reading test results 15 minutes after a simple operation is completed.

As described earlier, vitamin D is not actually a vitamin, but rather a hormone that promotes calcium absorption in the body. It has important health implications for both teenagers and children, as well as aged populations. People who don't get enough vitamin D will not only experience fatigue but also have their bones mature more slowly. The main cause is that low vitamin D levels make the body's mitochondria, which are where most of the body's cells' aerobic respiration occurs, less effective. Fortunately, vitamin D deficiency can be identified through testing and be treated under the guidance of a healthcare practitioner. Treatment options can vary for each individual, But in order to keep the body healthy, low vitamin D levels must be treated. A vitamin D pill can lessen the severity of COVID-19. In order to treat COVID-19, vitamin D should be suggested as an adjuvant therapy.

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