There are many hypotheses why respiratory diseases are only a problem in a certain season: cold, dry air, indoors, travel, solar ultraviolet radiation that kills pathogens, a yearly biorhythm of hormones, etc. Perhaps, that the seasonality of viruses and bacteria is responsible for this.
The authors analyzed the number of deaths from influenza and pneumonia in Norway in 1980-2000, and compared with the level of ultraviolet radiation and the vitamin D. Disease from influenza 2 months after reaching the minimum level of vitamin D, but this is probably due to the fact that the disease usually begins several weeks before death.
The maximum level of vitamin D is observed in mid-summer, and the minimum in February.
In women who avoid direct sunlight, the level of vitamin D is 25 nmol/L.
Norway is at 58-70 degrees of latitude, and vitamin D is synthesized on the skin only in the summer.
In the tropics the seasonality of the flu is not observed, but from 20-30 degrees latitude is already observed. At first glance this is unexpected, but at the 25th latitude in the end of June, 5 times more vitamin D is synthesized on the skin than at the end of December. It is known that vitamin D strengthens the immune system.
Most vitamin D is produced by the sun.
In the middle latitudes, many people have low levels of vitamin D, especially in the winter.
Elderly people produce four times less vitamin D than the 20-year-olds, under the influence of the same solar radiation.
In London (52nd latitude), vitamin D is not produced from October to March, as all UVB radiation is filtered by the ozone layer.The winter mortality in the UK is inversely proportional to the amount of sunlight.Each additional hour of the sun reduces mortality by 2.9%.
In vaccinated with live vaccine in February, the temperature rises 2 times more often than in vaccinated in June.In vaccinated in summer less antibodies are formed, 40% of those vaccinated in December secrete the virus, compared to 16% of those vaccinated in September.
There was no evidence of toxicity of vitamin D, even in the amount of 50,000 IU daily for 6 weeks, a single dose of 600,000 IU intramuscularly is also not toxic.
A randomized, double-blind, placebo-controlled study of the effect of vitamin D on the incidence of influenza. Children who received 1200 IU of vitamin D3 a day had 42% less flu.Vitamin D for the prevention of respiratory tract infections: A systematic review and meta-analysis. 2012, Charan, J Pharmacol Pharmacother
Systematic review and meta-analysis of the effect of vitamin D on the incidence of acute respiratory disease. Only randomized placebo-controlled trials are included.5 Vitamin D is associated with a 42% reduction in the incidence of children and 35% in adults.Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. 2013, Bergman, PLoS One
A similar systematic review and meta-analysis (11 studies): Vitamin D is associated with a 36% reduction in the risk of ARI, small daily doses are associated with a 49% reduction in the risk of ARI, while infrequent high doses of vitamin A are less effective and reduce risk ARV only by 14%.Vitamin D, innate immunity and outcomes in community acquired pneumonia. 2011, Leow, Respirology
Among patients admitted to the hospital with pneumonia, mortality in those who had a vitamin D deficiency (less than 30 nmol/L) was 12.7 times higher than among those who had a vitamin level higher than 50 nmol/L.Association of subclinical vitamin D deficiency in newborns with lower respiratory infection and their mothers. 2009, Karatekin, Eur J Clin Nutr
The level of vitamin D in newborns hospitalized with acute respiratory infection was significantly lower than in healthy newborns (9.12 vs 16.33 ng/mL).
The level of vitamin D in mothers of hospitalized newborns was also lower than in mothers of healthy babies (13.38 vs 22.79 ng/mL). A high correlation was observed between the level of vitamin D in newborns and their mothers.
The authors measured the level of vitamin D in the umbilical cord in 922 newborns.
In the next 3 months after birth, the risk of respiratory infections and other infections in infants with a vitamin level below 25 nmol/L was 2 times higher, than in infants with a vitamin level above 75 nmol/L. The risk of wheezing in children with low vitamin D at birth was 2-fold higher to five years of age than in infants with high levels of vitamin.
Infants, with a vitamin D level in the umbilical cord below 50 nmol/L, had bronchiolitis in their first year of life 6.2 times more often than those who had a vitamin level at birth above 75 nmol/L. Western countries, 40% of pregnant women and 50% of newborns have vitamin D deficiency. Vitamin D deficiency during pregnancy is associated with type 1 diabetes, multiple sclerosis, schizophrenia and respiratory diseases in children.Association of subclinical vitamin D deficiency with severe lower respiratory infection in Indian children under 5 y. 2004, Wayse, Eur J Clin Nutr
Children with a vitamin D level above 22.5 nmol/L suffered from pneumonia 91% less frequently. Exceptional GV over the course of 4 months reduced the risk of pneumonia by 58%.Serum 25-hydroxyvitamin D, mortality, and incident cardiovascular disease, respiratory disease, cancers, and fractures: a 13-y prospective population study. 2014, Khaw, Am J Clin Nutr
A prospective study of 14,000 people in the UK, followed by 13 years. The higher the vitamin D level, the lower the mortality rate, among those with a vitamin D level above 90 nmol/L, mortality was 34% lower than in people with a vitamin level of 30 nmol/L and lower, the risk of cardiovascular death was 38% lower, cancer 15% lower, respiratory disease 78% lower.An association of serum vitamin D concentrations <40 nmol/L with acute respiratory tract infection in young Finnish men. 2007, Laaksi, Am J Clin Nutr
Soldiers with low vitamin D levels (below 40 nmol/L) were 63% more likely to have respiratory illnesses than soldiers with a vitamin level higher than 40 nmol/L. Among those who smoked, the vitamin D level was lower than In non-smokers, soldiers who exercise more than 5 hours a week, the level of vitamin D was higher.Serum 25-hydroxyvitamin d and the incidence of acute viral respiratory tract infections in healthy adults. 2010, Sabetta, PLoS One
Adults with a vitamin D level above 38 ng/mL were ill 2.7 times less likely to have a disease duration of 4.9 times less. The influenza vaccine did not affect the incidence.On the epidemiology of influenza. 2008, Cannell, Virol J
A very interesting survey article on the epidemiology of influenza and vitamin D, it is worth reading in full. Among other things, it turns out that in numerous laboratory experiments and could not prove that a person with flu can infect a healthy person.Vitamin D: a new anti-infective agent? 2014, Borella, Ann N Y Acad Sci
Low level of vitamin D also correlates with intestinal infections, pneumonia, otitis media, clostridial infections, vaginosis, urinary tract infections, sepsis, dengue, hepatitis B, hepatitis C and HIV. Vitamin D is used in the treatment of osteoporosis, rheumatism and cancer Before the middle of the 20th century, tuberculosis was treated in sun baths in sanatoriums, and it was treated with fish oil, these different methods of treatment have one common component - vitamin D.Vitamin D for influenza. 2015, Schwalfenberg, Can Fam Physician
Tamiflu and Relenza are useless drugs that do more harm than good. I have seen how patients in nursing homes and staff begin because of them vomiting, diarrhea, hallucinations, delirium, and worsening cognitive function. The IOM recommends taking 600 IU vitamin D for those under 70 years old to reach the level of 50 nmol/L in 97.5% of people. However, their recommendation contains a statistical error, and in fact, you need to take 8800 IU to achieve this For several years, as I and my colleague have given vitamin D to patients, and most of them have a vitamin level of more than 100 nmol/L. We rarely see patients with influenza or ARD, and when we see, we give them shock doses of vitamin D (a one-time dose of 50,000 IU, or 10,000 IU three times a day for 2-3 days) Symptoms completely pass for 48-72 hours Vitamin D costs a penny for 1000 IU, that is, this treatment costs less dollar.Pandemic preparedness for swine flu in the United States. 2009, Edlich, J Environ Pathol Toxicol Oncol
Some health professionals may not want to be vaccinated against swine flu because the vaccine contains a mercury preservative thiomersal that can be harmful to health.It should check the level of vitamin D and make up for the deficit if necessary. the level of vitamin D is 50-75 ng/mL, and the optimal dose for adults is 4000-5000 IU per day.