key: cord-0717969-wwy69jdg
authors: Im, Jae Hyoung; Je, Young Soo; Baek, Jihyeon; Chung, Moon-Hyun; Kwon, Hea Yoon; Lee, Jin-Soo
title: Nutritional status of patients with coronavirus disease 2019 (COVID-19)
date: 2020-08-11
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2020.08.018
sha: fac85b3ac922176bca9820c310734a9023aa2c7a
doc_id: 717969
cord_uid: wwy69jdg

The relationship between immunity and nutrition is well known and its role in coronavirus disease 2019 (COVID-19) is also being paid greater attention. However, the nutritional status of COVID-19 patients is unknown. Vitamins B1, B6, B12, D (25-hydroxyvitamin D), folate, selenium, and zinc levels were measured in 50 hospitalized patients with COVID-19. A total of 76% of the patients were vitamin D deficient and 42% were selenium deficient. No significant increase in the incidence of deficiency was found for vitamins B1, B6, and B12. folate, and zinc in patients with COVID-19. The COVID-19 group showed significantly lower vitamin D values than the healthy control group (150 people, age/sex matching). Severe vitamin D deficiency (based on 10 ng/dL) was found in 24% of the patients in the COVID-19 group and 7.3% of the control group. Among 12 patients with respiratory distress, 11 (91.7%) were deficient in at least one nutrient. However, patients without respiratory distress showed deficiency in 30/38 people (78.9%, P-value 0.425). These results suggest that a deficiency of vitamin D or selenium may decrease the immune defenses against COVID-19 and cause progression to severe disease; however, more precise and large-scale studies are needed.

December 2019 and has since caused numerous fatalities and economic losses worldwide , (Nicola et al., 2020) . The mortality rate of COVID-19 varies significantly by country, race, and socioeconomic status (Aldridge et al., 2020) . The differences are believed to be caused by a variety of factors, including ethnicity, medical systems, and age structure. Factors such as poor socioeconomic status or weak immunity appear to increase vulnerability to COVID-19 (Grant et al., 2020) . It is well documented that individuals who are aging, have underlying illnesses, or live in long-term care facilities are more vulnerable to COVID-19 (D'Adamo et al., 2020) .

Decreased immunity is a significant risk factor for infection with respiratory viruses. Proper diet and nutrition are considered important elements for an optimal immune response to prevent infections (Calder et al., 2020 , Chandra, 1983 ; thus, improper intake and condition of these nutrients increase the disease burden. Evidence suggests that nutrients are involved in the development of COVID-19 (Rhodes et al., 2020a) ; however, no studies have been undertaken to assess nutrient deficiencies in COVID-19 patients directly. Therefore, we conducted a study to confirm the amounts of various nutrients in COVID-19 patients.

J o u r n a l P r e -p r o o f

This study was conducted on adults with COVID-19 admitted to Inha University Hospital, South Korea, from February to June 2020. Foreigners or children younger than 15 years were excluded. To diagnose the presence of COVID-19, a polymerase chain reaction assay (Allplex TM 2019-nCoV Assay kit, Seegene TM , Republic of Korea) was performed with samples from the upper or lower respiratory tract. COVID-19 infection severity was classified as i) without pneumonia, ii) pneumonia without oxygen treatment, iii) pneumonia with oxygen treatment, iv) high-flow oxygen treatment v) mechanical ventilator, and vi) extracorporeal membrane oxygenation (ECMO) or death.

All nutrients were analyzed within 7 days of admission (median number of days for analysis was 2 days after admission) and the following nutrients were investigated: vitamin B1, B6, B12, D (25-hydroxyvitamin D3), folate, selenium, and zinc. Specimens were sent to Seoul Clinical Laboratories Co. Ltd (Republic of Korea) except for folate and vitamin B12, which were sent to Green Cross Co. Ltd (Republic of Korea). 25-hydroxy vitamin D3 was tested by a validated liquid chromatography-tandem mass spectrometry method. High-Performance Liquid Chromatography for Vitamin B1 and B6, Electro-chemiluminescence binding assay for folate and vitamin B12, and Inductively coupled plasma -mass spectroscopy for Selenium and Zinc were used. The equipment, cut-off values, and references are described in Supplementary   Table 1. The 25-hydroxyvitamin D3 in COVID-19 patients was compared with the results of the control group who visited Inha University for their annual medical check-up. The control group was defined as those tested for 25-hydroxyvitamin D3 in February-June-the same season in which COIVD-19 patients came to our hospital. The control group was assigned 3:1 after ageand sex-matching with the COVID-19 group. No other nutrients except 25-hydroxyvitamin D3 had a control group. Student's t-test and chi-squared test were used to compare the vitamin D J o u r n a l P r e -p r o o f levels of the two groups. Any p-value < 0.05 was considered statistically significant. Data analysis was performed using SPSS statistical software, version 18 (SPSS Inc., Chicago, IL, USA).

During the study period, 83 patients with COVID-19 were hospitalized; however, 15 of them were excluded because they were children or foreigners. Therefore, the total number of potential candidates for this study was 68; however, 12 were missing prescriptions, and six were not examined within one week of hospitalization. Therefore, only 50 individuals were selected to have their nutrient levels assessed (zinc measurement was introduced from May, and only 25 individuals were tested for it). A total of 29 men and 21 women were included with a median age of 57.5 [IQR 34.5-68.0] years. The age distribution was as follows: two teenagers (15-19 years), eight in their 20s, five in their 30s, five in their 40s, eight in their 50s, 12 in their 60s, and 10 were 70 years or older.

According to the data, vitamin D deficiency was the most prevalent, with a deficiency (less than 20 ng/dl) in 76% of the patients and a severe deficiency (less than 10ng/dl) in 24%.

As for the other nutrients, deficiency of selenium was observed in 42% of the patients, pyridoxine in 6.1%, and folate in 4.0%. No patients were deficient in B1, B12, or Zinc. At least one missing nutrient was revealed in 82% of the patients. The median value of each nutrient and the deficiency percentages are shown in Table 1 .

In the comparison between the two groups, the average of 25 hydroxyvitamin-D3 among those with COVID-19 was 15.73 ng/dL, which was significantly lower than that of the control group, which was 25.03 ng/dL. The deficiency rate was 74.0% in the COVID-19 group and 43.3% in the control group. In terms of severe deficiencies, there were also differences between the two groups: 24% and 7.3%, respectively (Table 2 ).

In patients with mild COVID-19 infection (without pneumonia), vitamin D and selenium deficiencies were present in 66.7% and 44.4% of them, respectively. In contrast, the same deficiencies in patients whose severity was higher than the mechanical ventilator category were 80% and 100%, respectively. Of the 12 patients with respiratory distress, 11 were J o u r n a l P r e -p r o o f deficient in at least one nutrient. The percentages of nutrient-deficient patients according to the categories of infection severity are shown in Table 3 .

In this study, vitamin D and selenium deficiencies were the most prevalent.

Additionally, almost all COVID-19 patients with respiratory distress were classified as nutrient deficient. It is unclear whether individual nutrient deficiency affected immunity or whether nutrient deficiency simply led to a decline in the patients' overall condition. However, as it becomes increasingly clear that hyper-inflammation is a major component in the course of the severe progression of COVID-19, vitamin D, and selenium deficiency should be highlighted.

Vitamin D supports the production of antimicrobial peptides in the respiratory epithelium, reducing the likelihood of viral infections and decreasing the severity of symptoms (Barlow et al., 2011 , Bartley, 2010 . The dysregulation of the renin-angiotensin system is one of the primary mechanisms of lung injury in COVID-19 (Bourgonje et al., 2020 , Kong et al., 2013 . Furthermore, vitamin D upregulates anti-inflammatory mediators, which is vital when considering the hyper-inflammatory immune response caused by COVID-19 (Daneshkhah et al., 2020) . These mechanisms suggest that vitamin D-deficient patients may be more susceptible to become infected with COVID-19 and be more likely to develop severe symptoms. Compared to the control group, the COVID-19 group showed a high percentage of vitamin D deficiency in the present study. Vitamin D supplements have been shown to be of uncertain benefit in treating or preventing most diseases, except rickets or osteomalacia (Autier et al., 2017) . However an important exception to this general trend is in the case of upper respiratory tract infections. A meta-analysis conducted in 2017 showed that vitamin D supplements protect against acute respiratory infections (Martineau et al., 2017) . In our study, even the control group showed an incidence of vitamin D deficiency of 43.3%, so it was difficult to conclude that vitamin D deficiency directly increases the risk of infection. However, considering the high mortality rate in long-term care facilities or high latitude countries (Rhodes et al., 2020a) In selenium-deficient mice, there were no differences in the influenza virus-specific antibodies compared to mice with adequate selenium levels. However, the levels of macrophages, CD8 +, and CD4 + T cells were lower, suggesting that selenium deficiency affects cellular immunity (Beck et al., 2003) . Influenza virus-infected models in seleniumdeficient mice (Beck et al., 2001) and in vitro influenza infection models of selenium-deficient human bronchial epithelial cells (Jaspers et al., 2007) have shown that inflammation may be increased in response to high oxidative stress levels. Among HIV-1-infected individuals, the lower the serum selenium concentration, the lower the number of CD4 + T cells, leading to more significant HIV-1 disease progression (Baum et al., 1997 , Look et al., 1997 . Another study suggested that low selenium levels were associated with reduced natural killer (NK) cellmediated cytotoxicity in HIV-1-infected individuals (Mantero-Atienza et al., 1991) . In

dysfunction and lymphopenia (Tay et al., 2020) ; therefore, selenium deficiency needs to be considered in severe cases of COVID-19. In a study involving previously healthy Koreans, the mean selenium levels were 103.2 and 120.8 μg/L in males and females, respectively. In this study, the median selenium concentrations were 101.4 and 96.7 μg/L in males and females, respectively. Additionally, 42% of COVID-19 patients were found to have selenium levels below the cut-off. It is unknown whether selenium supplementation could influence progression severity of COVID-19.

In our study, only 6% of COVID-19 patients were deficient in pyridoxal-5-phosphate (PLP); however, 96% were deficient in pyridoxal or 4PA. PLP, the active form of vitamin B6 (pyridoxine), is an essential cofactor in many inflammatory pathways and is gradually depleted J o u r n a l P r e -p r o o f during inflammation (Paul et al., 2013) . In our study, PLP did not drop significantly. Probably, our study was less affected because it was conducted within seven days of patient admission.

However, 4-pyridoxic acid and pyridoxal may indicate other micronutrient deficiencies that we did not measure. Additionally, some COVID-19 patients have longer treatment periods due to acute lung injury; therefore, even if the PLP levels are acceptable, it is necessary to study how the PLP status changes in patients with 4-pyridoxic acid/pyridoxal deficiency during severe COVID-19 infection.

It is worth noting that this study had several limitations. First, it was a study conducted at a single center with a relatively small number of patients. However, compared to the averages in Korea, an apparent deficiency of vitamin D and selenium was observed. Second, in this study, nutrients such as vitamin D were only measured from February to June, and most of the patients with COVID-19 in this study lived in cities. However, this study did not aim to find an exact fraction of the specific nutritional deficiency, but rather to show the general trend of deficiency and the importance of nutrition in the prevention of severe cases of COVID-19. Third, many indicators of nutritional status are unreliable during infections. The Vitamin D Binding Protein is a positive acute phase reactant after infections; it may lower the level of 25-hydroxyvitamin D (Silva and Furlanetto, 2015) . A decrease in other nutrients may also be the result of an infection. However, because our study was conducted in the early stages of infection, these outcomes should not be considered a result of COVID-19. Additional research is needed, including free vitamin D assay (Bikle et al., 2017) .

This study investigated the status of various nutrients in patients with COVID-19. The results show that many patients were deficient in vitamin D and selenium. Additionally, all severely ill patients with COVID-19 where deficient in more than one nutrient. Therefore, we suggest a possibility that nutritional deficiencies may favor the onset of COVID-19 and increase the severity of the disease. Further research is needed on the impact of nutritional J o u r n a l P r e -p r o o f Vitamin B1 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) Vitamin B6 (PLP) 2 (11.1%) 1 (3.1%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) Folate 1 (20.4%) 1 (3.1%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) Vitamin B12 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) Selenium 8 (44.4%) 13 (40.6%) 8 (66.7%) 6 (66.7%) 4 (100.0%) 3 (100.0%) Zinc 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) One or more deficiency 13 (72.2%) 28 (87.5%) 11 (91.7%) 8 (88.9%) 5 (100.0%) 4 (100.0%) Pneumonia includes cases with or without oxygen supply. Oxygen includes high-flow nasal canula, mechanical ventilator, and ECMO/death.

High-flow nasal canula includes mechanical ventilator and ECMO/Death. Mechanical ventilator includes ECMO/Death and one death.

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This work was supported by a research grant from Inha University hospital.

Conceptualization: Im JH and Lee JS. 

This study had no funding.

This study was approved by the local ethics committee, which waived the need for informed consent.

All authors declare no conflict of interest related to this study.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.