Health risks and potential remedies during prolonged lockdowns for coronavirus disease - 2019 (COVID-19) - De Gruyter
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Diagnosis 2020; 7(2): 85–90
Opinion Paper
Giuseppe Lippi*, Brandon M. Henry, Chiara Bovo and Fabian Sanchis-Gomar
Health risks and potential remedies during
prolonged lockdowns for coronavirus disease
2019 (COVID-19)
https://doi.org/10.1515/dx-2020-0041
Received March 26, 2020; accepted March 26, 2020; previously
Introduction
published online April 7, 2020
Coronavirus disease 2019, abbreviated to COVID-19, is a
Abstract: As coronavirus disease 2019 (COVID-19) pan- viral infectious disease caused by severe acute respira-
demic continues, an increasing number of countries tory syndrome coronavirus 2 (SARS-CoV-2) [1, 2]. As with
and territories are adopting restrictive measures based other members of the Coronaviridae family, inter-human
on physical (“social”) distancing, aimed at preventing transmission of this microorganism is mostly due to res-
human-to-human transmission and thereby limiting piratory tract infection, mediated by the so-called res-
virus propagation. Nationwide lockdowns, encompass- piratory droplets, which are formed by water and various
ing mass quarantine under stay-at-home ordinances, inclusions, and can be generated while talking, breath-
have already been proven effective to contain the COVID- ing, coughing or sneezing [3]. Human droplets are circu-
19 outbreak in some countries. Nevertheless, a pro- lar elements with ~5 μm diameter that rapidly fall to the
longed homestay may also be associated with potential ground under gravity after being produced, which usually
side effects, which may jeopardize people’s health and limits the transmission distance at less than 1 m during
thus must be recognized and mitigated in a way without normal breathing (Figure 1) [4]. Some additional vehicles
violating local ordinances. Some of the most important of potential contagion have been identified (e.g. direct
undesirable consequences of prolonged homestay such contact with infected environmental or biological materi-
as physical inactivity, weight gain, behavioral addiction als such as feces or saliva) [5–7], though respiratory drop-
disorders, insufficient sunlight exposure and social iso- lets remain the largest source of contagion.
lation will be critically addressed in this article, which The most recent statistics of the World Health Organi-
also aims to provide some tentative recommendations zation (WHO) attests that SARS-CoV-2 has already infected
for the alleviation of side effects. nearly 635,000 persons around the world, causing over
30,000 deaths [8]. These numbers are inevitably destined
Keywords: coronavirus; COVID-19; epidemics; health;
to grow as definitive vaccines and cures for COVID-19 are
outbreak.
unlikely to be identified soon [9]. As such, a combination
of contact tracing and social isolation seems to be the
most effective strategy to control the COVID-19 outbreak
[10], as this strategy will be effective for flattening the
curve of new infections due to human-to-human trans-
*Corresponding author: Prof. Giuseppe Lippi, Section of Clinical mission, limiting morbidity, mortality and the ensuing
Biochemistry, Department of Neuroscience, Biomedicine and surge of demand on healthcare system.
Movement, University Hospital of Verona, Piazzale LA Scuro, 37134
Verona, Italy, Phone: +39-045-8124308, Fax: +39-045-8122970,
E-mail: giuseppe.lippi@univr.it
Brandon M. Henry: Cardiac Intensive Care Unit, The Heart Institute, Lockdown
Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
Chiara Bovo: Medical Direction, University Hospital of Verona, Lockdown, a term conventionally used as surrogate
Verona, Italy
for “mass quarantine”, is typically based on “stay-at-
Fabian Sanchis-Gomar: Department of Physiology, Faculty of
Medicine, University of Valencia and INCLIVA Biomedical Research
home” or “shelter-in-place” ordinances given by a public
Institute, Valencia, Spain; and Division of Cardiovascular Medicine, (either national or regional) government or authority,
Stanford University School of Medicine, Stanford, CA, USA for imposing social distancing and hence limiting or86 Lippi et al.: Health risks of lockdown during viral outbreaks
gain, behavioral addiction disorders, insufficient sunlight
exposure and social isolation will be critically addressed
in this article, which also aims to provide some tentative
recommendations for the alleviation of side effects. These
problems and our recommended remedies are summa-
rized in Table 1.
Physical inactivity
The dramatic reduction of physical activity due to man-
datory homestay is perhaps one of the most apparent
Figure 1: Severe acute respiratory syndrome coronavirus 2 (SARS- consequences of complete lockdown, not only for active
CoV-2) propagation by droplets. individuals habitually practicing recreational sports, but
also for those who go to work by walking or cycling, or
whose job includes physical activity of some sorts.
completely abolishing the movement of the population It has already been defined that the combination of
inside and outside a specific area. It is hence mostly used abrupt interruption of physical exercise and prolonged
as for counteracting an ongoing outbreak, mandating inactivity may promote many adverse health changes,
residents to stay inside their homes, except for carrying including development of insulin resistance, muscle
out essential activities (health visits, tending to a vulner- atrophy and bone loss, decreased aerobic capacity,
able person, purchasing medicines, food and beverages) increased blood pressure and heart frequency, fatty liver
or providing essential work (e.g. healthcare and social disease and/or nonalcoholic steatohepatitis, dyslipi-
care sectors, police and armed forces, firefighting, water demia, as well as higher risk of collapsing upon resum-
and electricity supply, critical manufacturing). Other non- ing exercise [16]. The important biological and metabolic
essential activities are hence stopped or carried out from adaptations would hence translate into a considerable
home [11, 12]. higher risk of developing osteoporosis [17], diabetes [18],
At the time of writing this article (March 30, 2020), cardiovascular disease [19], cancer [20], dementia [21] as
nationwide restrictions for limiting the spread of SARS- well as overweight/obesity [22], among others. Overall, the
CoV-2 infections have been established by over 50 coun- enhanced physical inactivity-attributable disease burden
tries around the world, including the UK, Italy, Spain, not only fosters a remarkably higher risk of disability, but
France, Germany, Austria, South Africa, India, Colombia, is also associated with a nearly 24% increased risk of all-
New Zealand and several US states, with many others to cause mortality among the general population [23].
follow as soon as the numbers of COVID-19 cases con- The current WHO global recommendations on physi-
tinue to rise exponentially. Currently, we can estimate that cal activity for health promotion and maintenance indi-
over 280 million people are under lockdown throughout cate that adults should engage in not less than 150 min
Europe, 150 million in the US, nearly 1.3 billion in India per week of moderate-intensity aerobic physical activity,
and still 50–60 million in China. Overall, it can hence be or not less than 75 min per week of vigorous-intensity
estimated that over one-third of humanity is subjected to aerobic physical activity, or an equivalent combination of
some form of restrictive measures [13]. This strategy has moderate- and vigorous-intensity activity [24]. This most
been proven effective for containing the COVID-19 out- frequently translates into the practice of recreational or
break in China, also limiting the exportation of infected leisure activities such as walking, cycling, swimming,
cases outside the country [14, 15]. Nevertheless, stay-at- gardening, hiking, dancing and household working.
home orders may also be associated with numerous side Additionally, the WHO recommends performing some
effects, especially when the lockdown is protracted for muscle-strengthening activities, involving major muscle
months, thereby disrupting social habits and jeopardiz- groups, for 2 or more days on a weekly basis.
ing personal health. Strategies, which do not violate local Fulfillment of these recommendations is inherently
ordinances, need to be urgently identified and established challenging for citizens residing in lockdown areas, as
for preventing these derangements. movements outside one’s residence are almost totally
To that end, the most important undesirable effects banned. People not involved in essential services are forced
of prolonged homestay such as physical inactivity, weight to stay inside their houses for weeks (or even months),Lippi et al.: Health risks of lockdown during viral outbreaks 87
Table 1: Health risks and potential remedies during prolonged nationwide lockdown for coronavirus disease 2019 (COVID-19).
Risk factor Most relevant health Remedies
consequences
Physical inactivity – Osteoporosis – Keep enough distance while exercising outside
– Diabetes – Practice indoor exercise
– Cardiovascular disease – Use video- or app-guided equipment-free training
– Cancer – Use the stairs
– Dementia – Avoid sports injuries
Weight gain – Diabetes – Hypocaloric diets
– Cardiovascular disease – Reduced total fat content
– Pulmonary embolism – Prefer low-carbohydrate and high-protein foods
– Cancer – Increase intake of dietary fiber
– Low back pain – Supplement diet with immunomodulatory foods
– Osteoarthritis
– Disability
Behavioral – Psychological disturbances – Controlled and balanced usage of electronic devices
addiction – Neurological complications – Use of external stoppers
– Musculoskeletal disorders – Software programs controlling usage time
– E-thrombosis – Development of personal inventories
Insufficient – Low vitamin D levels – Vitamin D dietary supplementation
sunlight exposure – Diet enriched in foods with high vitamin D
Social isolation – Depression – Delivering groceries and essential medicines
– Anxiety – Reinforce social care measures
– Misidentification of health – More frequent contacts with smartphone or social
deterioration media
only allowed to move sporadically for health or alimen- other than exercise bands, fitness ball or weights can still
tary purposes. Nevertheless, the shelter-in-place orders be performed, driven by video- or app-guided equipment-
established by some countries, like Italy and Germany, free training [29]. Basic things that can be found at home
for example [25], enable some outdoor physical activity, may also help, such as the stairs for climbing, performing
provided that a sufficient interpersonal distance can be step exercise or even strength training.
guaranteed (i.e. >1 m, >1.5 m or >2 m depending on local Another important aspect is the absolute need to avoid
ordinances), and that the exercise is completed in close any type of sports injury (direct, indirect or overuse) while
proximity of one’s home residence. The maintenance of practicing exercise [30]. As most healthcare resources,
a sufficient interpersonal distance is crucial, almost una- especially emergency departments (EDs) and intensive
voidable, as SARS-CoV-2 is mostly transmitted by drop- care units (ICUs), are now overwhelmed managing the
lets [26]. The risk of infection may hence be enormously massive number of COVID-19 patients requiring urgent
magnified in subjects practicing narrow sports activities, care [31], preventing any additional strain of care due to
such as contact sports or side-by-side running or cycling, unwarranted injuries on an already exhausted system is
as a consequence of increased ventilatory demand, which vital.
is then accompanied by increase of respiratory frequency
(i.e. from 15 to 20, up to 50 breaths per min) and enhanced
volume of exhaled air [27, 28]. An exception to total stay- Weight gain
at-home rule for performing some forms of outdoor exer-
cise may contribute to counteract the detrimental changes The risk of weight gain, up to developing overweight or
resulting from prolonged physical inactivity. Engagement obesity, is one of the most significant implications of phys-
in some forms of indoor physical activity is another viable ical inactivity [22]. Overweight and obesity, defined by
solution. Although fast (power) walking, running and the WHO as a body mass index (BMI) ≥25 and ≥30 kg/m2,
cycling are unfeasible for the vast majority of subjects respectively [32], are accompanied by a kaleidoscope of
who are lacking indoor exercise equipment (e.g. tread- metabolic derangements, ultimately increasing the risk
mills, stationary bikes, etc.), strength or aerobic workout of many pathologies such as diabetes, cardiovascular
without the need of very specific and expensive equipment disease, pulmonary embolism, cancers, low back pain,88 Lippi et al.: Health risks of lockdown during viral outbreaks
osteoarthritis and disability [33]. Nonetheless, as weight D [25-hydroxycholecalciferol; 25(OH)D]. It has now been
gain is also commonplace during leave periods [34], it is established that sunlight exposure [especially to ultravio-
reasonable to hypothesize that prolonged shelter-in-place let B (UVB) light] is the major limiting step in the endog-
ordinances will predispose to weight gain, an aspect mag- enous generation of vitamin D, whereby sunlight mediates
nified by the unhealthy dietary habits that very frequently the conversion of precholecalciferol (previtamin D3) into
accompany prolonged television viewing [35]. Some spe- cholecalciferol (vitamin D3), which is then converted into
cific measures should be recommended to people forced 25(OH)D by the liver enzyme vitamin D 25-hydroxylase [43].
into a prolonged indoor stay, which would include caloric Several lines of evidence now attest that vitamin D not only
restriction through hypocaloric diets (encompassing also is essential for bone health [44], but may also produce a
reduced portion size), reduction of total fat content, low- vast array of pleiotropic (beneficial) effects, including
carbohydrate and high-protein foods, combined with lowering the risk of developing pathologies such as car-
increased intake of dietary fiber [36]. diovascular and autoimmune diseases, cancer, allergy and
As COVID-19 is characterized by considerable asthma, mental disorders, metabolic syndrome and diabe-
derangement of the immune response, especially involv- tes, among others [45]. The intricate interplay of vitamin
ing and injuring helper and suppressor T cells [37], a diet D with immune system and infectious diseases is another
enriched with immunomodulatory foods such as pro- and important aspect, which has been the focus of many recent
pre-biotics and some vitamins (i.e. vitamin A, C and D) studies. Vitamin D receptors are highly expressed by many
may also be advisable [38, 39]. immune cells, including monocytes, and T and B lympho-
cytes [46]. As the function of these cells is modulated by
vitamin D, deficiency in this hormone is frequently associ-
Behavioral addiction disorders ated with increased susceptibility to, and severity of, many
infectious diseases [47]. In particular, some recent studies
provided credible evidence that subjects with vitamin D
Prolonged indoor stay is unavoidably accompanied by
deficiency may be at significantly higher risk of develop-
longer time spent watching television, online gaming or
ing respiratory tract infections [48]. As SARS-CoV-2 is a
social networking, thus potentially worsening behavioral
coronavirus primarily causing a respiratory viral infection
(i.e. internet, screen, or television) addiction disorders.
[49], vitamin D insufficiency due to inadequate sunlight
The most common side effects encompass psychological
may occur, especially in those countries where food forti-
disturbances (e.g. sleep deprivation, self-harm), neuro-
fication has not been introduced [50]. As such, guidelines
logical complications (e.g. eye strain, headache), mus-
preventing the risk of vitamin D insufficiency seem advis-
culoskeletal disorders (i.e. low back pain, carpal tunnel
able. Increased vitamin D intake can be achieved either by
syndrome) [40, 41] as well as increased risk of immobility-
administering vitamin D as a dietary supplement (carefully
related venous thrombosis (i.e. the so-called e-thrombo-
weighing the risk of causing toxicity from hypervitamino-
sis) [42]. Remedies for this problem are more challenging
sis D) or enriching the diet with foods that have a relatively
to identify than those for managing the classic forms of
high content of vitamin D, such as fatty fish, cod liver oil
behavioral addiction disorders, as a pre-existing organic
and egg yolks [51].
cause (e.g. psychological vulnerability, psychoticism) is
mostly lacking during prolonged lockdowns. The most
effective measures would hence encompass a controlled
and balanced usage of electronic devices, the adoption
of external stoppers (events or activities persuading the
Social isolation
user to log off), software programs controlling user’s
As the outbreak progresses with an increasing number of
time and development of inventories to track personal
countries implementing restrictive measures, the number
activities [40].
of people isolated at home increases in parallel. It is now
established that social isolation must be regarded as a
primary public health concern in the elderly, as it ampli-
Insufficient sunlight exposure fies the burden of neurocognitive, mental, cardiovascular
and autoimmune problems, as well as depression and
Insufficient sunlight exposure is another obvious con- anxiety [52]. Moreover, recent evidence has demonstrated
sequence of prolonged indoor stay, which would then that sedentary behaviors in the youth may also be an
be accompanied by reduced level of circulating vitamin important cause of depression and anxiety [53]. As such,Lippi et al.: Health risks of lockdown during viral outbreaks 89
self-isolation should be seen as a global healthcare and References
societal issue.
Besides the need to find some reliable and sustain- 1. Coronaviridae Study Group of the International Committee on
Taxonomy of V. The species Severe acute respiratory syndrome-
able means for delivering adequate amounts of gro-
related coronavirus: classifying 2019-nCoV and naming it SARS-
ceries and essential medicines to those who may be CoV-2. Nat Microbiol 2020;5:536–44.
unable to leave their homes autonomously during pro- 2. Lippi G, Sanchis-Gomar F, Henry BM. Coronavirus disease 2019
longed lockdown periods, counteracting the mounting (COVID-19): the portrait of a perfect storm. Ann Transl Med 2020;
burden of depression and anxiety becomes vital. Direct doi: 10.21037/atm.2020.03.157.
3. Guo YR, Cao QD, Hong ZS, Tan YY, Chen SD, Jin HJ, et al. The ori-
contact with relatives and friends is unfeasible where
gin, transmission and clinical therapies on coronavirus disease
very restrictive measures have been applied, such that 2019 (COVID-19) outbreak – an update on the status. Mil Med
other forms of social contact should be urgently estab- Res 2020;7:11.
lished for alleviating the unfavorable psychological 4. Atkinson J, Chartier Y, Pessoa-Silva CL, Jensen P, Li Y, Seto WH,
consequences. This would also enable the timely iden- editors. Natural ventilation for infection control in health-care
tification of any potential health deteriorations, espe- settings. Geneva: World Health Organization; 2009. Annex C,
Respiratory droplets. Available at: https://www.ncbi.nlm.nih.
cially among individuals with pre-existing diseases. The
gov/books/NBK143281/. Last accessed: March 25, 2020.
obvious solutions to all these problems encompass a 5. van Doremalen N, Bushmaker T, Morris DH, Holbrook MG,
reinforcement of social care measures, as well as more Gamble A, Williamson BN, et al. Aerosol and surface stability of
frequent use of smartphones or online contacts, which SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med 2020;
shall be made available to those who lack sufficient eco- doi: 10.1056/NEJMc2004973.
6. Zhang J, Wang S, Xue Y. Fecal specimen diagnosis 2019 novel
nomic resources.
coronavirus-infected pneumonia. J Med Virol 2020; doi:
10.1002/jmv.25742.
7. To KK, Tsang OT, Chik-Yan Yip C, Chan KH, Wu TC, Chan JM, et al.
Conclusions Consistent detection of 2019 novel coronavirus in saliva. Clin
Infect Dis 2020; doi: 10.1093/cid/ciaa149.
8. World Health Organization. Coronavirus disease 2019 (COVID-
As the COVID-19 outbreak continues its seemingly 19) Situation Report – 65. Available at: https://www.who.int/
unstoppable course, and social distancing becomes the emergencies/diseases/novel-coronavirus-2019/situation-
norm worldwide at least until a vaccine against SARS- reports. Last accessed: March 25, 2020.
9. Han Q, Lin Q, Jin S, You L. Coronavirus 2019-nCoV: a brief per-
CoV-2 becomes available, we are strongly persuaded
spective from the front line. J Infect 2020;80:373–7.
that nationwide lockdowns are a kind of “necessary 10. Hellewell J, Abbott S, Gimma A, Bosse NI, Jarvis CI, Russell TW,
evil” for preventing an otherwise wide-reaching disas- et al. Feasibility of controlling COVID-19 outbreaks by isolation
ter. It can be reasonably estimated that COVID-19 may of cases and contacts. Lancet Glob Health 2020;8:e488–96.
kill over 50 million people around the world if appropri- 11. Babic B, Gerke S, Evgeniou T, Cohen IG. Algorithms on regula-
tory lockdown in medicine. Science 2019;366:1202–4.
ate restrictive measures are not urgently established [2],
12. MacIntyre CR. On a knife’s edge of a COVID-19 pandemic: is
thus potentially causing more causalities than the noto-
containment still possible? Public Health Res Pract 2020:30.
rious Spanish (years 1918–1920), Asian (years 1957–1958) pii: 3012000.
and swine (years 2009–2010) flu pandemics combined 13. The Brussels Time. Coronavirus: nearly a billion people in lock-
[54]. As social distancing and homestay remain the down. Available at: https://www.brusselstimes.com/all-news/
most effective restrictive measures to stop the exponen- world-all-news/102043/nearly-a-billion-people-in-lockdown-
across-the-world/. Last accessed: March 25, 2020.
tial growth of this contagion, efficient remedies must
14. Lau H, Khosrawipour V, Kocbach P, Mikolajczyk A, Schubert
be identified and readily put into action to prevent the J, Bania J, et al. The positive impact of lockdown in Wuhan on
risk of developing unwarranted health consequences containing the COVID-19 outbreak in China. J Travel Med 2020;
from prolonged indoor gatherings during nationwide doi: 10.1093/jtm/taaa037.
lockdowns. 15. Wells CR, Sah P, Moghadas SM, Pandey A, Shoukat A, Wang Y,
et al. Impact of international travel and border control measures
on the global spread of the novel 2019 coronavirus outbreak.
Author contributions: All authors have accepted respon- Proc Natl Acad Sci USA 2020; doi: 10.1073/pnas.2002616117.
sibility for the entire content of this manuscript and 16. Lippi G, Henry MB, Sanchis-Gomar F. Physical inactivity and
approved its submission. cardiovascular disease at the time of coronavirus disease 2019
(COVID-19). Eur J Prev Cardiol 2020; in press.
Research funding: None declared.
17. Castrogiovanni P, Trovato FM, Szychlinska MA, Nsir H, Imbesi R,
Employment or leadership: None declared. Musumeci G. The importance of physical activity in osteoporo-
Honorarium: None declared. sis. From the molecular pathways to the clinical evidence. Histol
Competing interests: Authors state no conflict of interest. Histopathol 2016;31:1183–94.90 Lippi et al.: Health risks of lockdown during viral outbreaks
18. Bhaskarabhatla KV, Birrer R. Physical activity and diabetes mel- 37. Qin C, Zhou L, Hu Z, Zhang S, Yang S, Tao Y, et al. Dysregulation
litus. Compr Ther 2005;31:291–8. of immune response in patients with COVID-19 in Wuhan, China.
19. Lippi G, Sanchis-Gomar F. An estimation of the worldwide epi- Clin Infect Dis 2020; doi: 10.1093/cid/ciaa248.
demiologic burden of physical inactivity-related ischemic heart 38. Wichers H. Immunomodulation by food: promising concept
disease. Cardiovasc Drugs Ther 2020;34:133–7. for mitigating allergic disease? Anal Bioanal Chem
20. Sanchis-Gomar F, Lucia A, Yvert T, Ruiz-Casado A, Pareja- 2009;395:37–45.
Galeano H, Santos-Lozano A, et al. Physical inactivity and low 39. Azad MA, Sarker M, Wan D. Immunomodulatory effects of probi-
fitness deserve more attention to alter cancer risk and progno- otics on cytokine profiles. Biomed Res Int 2018;2018:8063647.
sis. Cancer Prev Res (Phila) 2015;8:105–10. 40. Cash H, Rae CD, Steel AH, Winkler A. Internet addiction: a
21. Lee J. The relationship between physical activity and dementia: brief summary of research and practice. Curr Psychiatry Rev
a systematic review and meta-analysis of prospective cohort 2012;8:292–8.
studies. J Gerontol Nurs 2018;44:22–9. 41. World Health Organization. Public health implications of exces-
22. Pietilainen KH, Kaprio J, Borg P, Plasqui G, Yki-Jarvinen H, Kujala sive use of the internet, computers, smartphones and similar
UM, et al. Physical inactivity and obesity: a vicious circle. Obe- electronic devices. Geneva, Switzerland: WHO Press, World
sity (Silver Spring) 2008;16:409–14. Health Organization, 2014.
23. Mok A, Khaw KT, Luben R, Wareham N, Brage S. Physical activity 42. Lippi G, Mattiuzzi C, Favaloro EJ. e-thrombosis: epidemiology,
trajectories and mortality: population based cohort study. Br physiopathology and rationale for preventing computer-related
Med J 2019;365:l2323. thrombosis. Ann Transl Med 2018;6:344.
24. World Health Organization. Physical activity and adults. Avail- 43. Lippi G, Cervellin G, Danese E. Indoor tanning a Gianus Bifrons:
able at: https://www.who.int/dietphysicalactivity/factsheet_ vitamin D and human cancer. Adv Clin Chem 2018;83:183–96.
adults/en/. Last accessed: March 25, 2020. 44. Lippi G, Targher G. Are we overrating the extra-skeletal benefits
25. Lazzerini M, Putoto G. COVID-19 in Italy: momentous decisions of oral vitamin D supplementation? Ann Transl Med 2019;7:499.
and many uncertainties. Lancet Glob Health 2020; doi: 10.1016/ 45. Targher G, Pichiri I, Lippi G. Vitamin D, thrombosis, and
S2214-109X(20)30110-8. hemostasis: more than skin deep. Semin Thromb Hemost
26. Yuen KS, Ye ZW, Fung SY, Chan CP, Jin DY. SARS-CoV-2 and 2012;38:114–24.
COVID-19: the most important research questions. Cell Biosci 46. Prietl B, Treiber G, Pieber TR, Amrein K. Vitamin D and immune
2020;10:40. function. Nutrients 2013;5:2502–21.
27. McKenzie DC. Respiratory physiology: adaptations to high-level 47. Aranow C. Vitamin D and the immune system. J Investig Med
exercise. Br J Sports Med 2012;46:381–4. 2011;59:881–6.
28. Aliverti A. The respiratory muscles during exercise. Breathe 48. Beard JA, Bearden A, Striker R. Vitamin D and the anti-viral state.
(Sheff) 2016;12:165–8. J Clin Virol 2011;50:194–200.
29. Sullivan AN, Lachman ME. Behavior change with fitness techno- 49. Moriyama M, Hugentobler WJ, Iwasaki A. Seasonality of respira-
logy in sedentary adults: a review of the evidence for increasing tory viral infections. Annu Rev Virol 2020; doi: 10.1146/annurev-
physical activity. Front Public Health 2016;4:289. virology-012420-022445.
30. Maffulli N, Del Buono A, Oliva F, Giai Via A, Frizziero A, Baraz- 50. Kennel KA, Drake MT, Hurley DL. Vitamin D deficiency in adults:
zuol M, et al. Muscle injuries: a brief guide to classification and when to test and how to treat. Mayo Clin Proc 2010;85:752–7;
management. Transl Med UniSa 2015;12:14–8. quiz 7–8.
31. Fisher D, Heymann D. Q&A: the novel coronavirus outbreak caus- 51. Pilz S, Marz W, Cashman KD, Kiely ME, Whiting SJ, Holick
ing COVID-19. BMC Med 2020;18:57. MF, et al. Rationale and plan for vitamin D food fortification:
32. World Health Organization. Obesity and overweight. Available a review and guidance paper. Front Endocrinol (Lausanne)
at: https://www.who.int/news-room/fact-sheets/detail/obesity- 2018;9:373.
and-overweight. Last accessed: March 25, 2020. 52. Armitage R, Nellums LB. COVID-19 and the consequences of
33. Djalalinia S, Qorbani M, Peykari N, Kelishadi R. Health impacts isolating the elderly. Lancet Public Health 2020; doi: 10.1016/
of obesity. Pak J Med Sci 2015;31:239–42. S2468–2667(20)30061-X.
34. Diaz-Zavala RG, Castro-Cantu MF, Valencia ME, Alvarez-Hernan- 53. Belair MA, Kohen DE, Kingsbury M, Colman I. Relationship
dez G, Haby MM, Esparza-Romero J. Effect of the holiday season between leisure time physical activity, sedentary behaviour
on weight gain: a narrative review. J Obes 2017;2017:2085136. and symptoms of depression and anxiety: evidence from a
35. Harris JL, Bargh JA. Television viewing and unhealthy diet: impli- population-based sample of Canadian adolescents. BMJ Open
cations for children and media interventions. Health Commun 2018;8:e021119.
2009;24:660–73. 54. Saunders-Hastings PR, Krewski D. Reviewing the history of
36. Astrup A. Dietary management of obesity. JPEN J Parenter Enteral pandemic influenza: understanding patterns of emergence and
Nutr 2008;32:575–7. transmission. Pathogens 2016:5. pii: E66.You can also read
