On 2014 Nov 30, Harri Hemila commented:

Musher DM, 2014 conclude their paper by stating that RCTs are needed to determine whether the antiinflammatory activity of macrolides or statins is beneficial in treating CAP.

I would like to propose that RCTs are also needed to determine whether vitamin C is beneficial in treating CAP. In dozens of animal studies, vitamin C protected against infections by various viruses and bacteria, implying that the vitamin may influence incidence and severity of some infections Hemilä 2006, pp. 5-9, 105-21.

In the early 20th century, Alfred Hess carried out extensive studies of scurvy and summarized a large series of autopsy findings as follows: “pneumonia, lobular or lobar, is one of the most frequent complications [of scurvy] and causes of death” and “secondary pneumonias, usually broncho-pneumonic in type, are of common occurrence, and in many [scurvy] epidemics constitute the prevailing cause of death”, see Hemilä H, 2007. In this journal, Hess 1932 commented that in “infantile scurvy … a lack of the antiscorbutic factor which leads to scurvy, at the same time predisposes to infections [particularly of the respiratory tract]. … Similar susceptibility to infections goes hand in hand with adult scurvy.” Thus, deficiency of vitamin C and pneumonia may be associated. Deficiency of vitamin C is not rare even nowadays Schleicher RL, 2009.

Furthermore, vitamin C has reduced the duration and severity of the common cold in well-nourished people suggesting that the vitamin may have effects on the respiratory system even in the absence of frank deficiency Hemilä H, 2013.

Hemilä H, 2013 carried out a Cochrane review and found 3 controlled trials that looked at whether vitamin C prevents pneumonia and 2 that looked at whether it might help in curing pneumonia. Each of the 5 studies found that vitamin C supplementation was significantly beneficial against pneumonia. Two of them were placebo-controlled RCTs.

Pitt HA, 1979 administered vitamin C to US marine recruits and reported 7 cases of pneumonia in the placebo-group compared with 1 case in the vitamin C group. Hunt C, 1994 administered vitamin C to elderly people who were admitted to hospital in the UK because of bronchopneumonia or acute exacerbation of chronic bronchitis. They reported a significant decrease in the “total respiratory score” by vitamin C administration, and 5 deaths in the placebo group compared with 1 death in the vitamin C group. Hunt et al. tested the effect of vitamin C “over and above those of normal medication (mainly antibiotics and cough medicines) to which all participants were exposed” so that all their patients received antibiotics and vitamin C was not an alternative to them.

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have a high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied, especially in pneumonia patients with low plasma vitamin C levels.

On 2014 Nov 30, Harri Hemila commented:

Musher DM, 2014 conclude their paper by stating that RCTs are needed to determine whether the antiinflammatory activity of macrolides or statins is beneficial in treating CAP.

I would like to propose that RCTs are also needed to determine whether vitamin C is beneficial in treating CAP. In dozens of animal studies, vitamin C protected against infections by various viruses and bacteria, implying that the vitamin may influence incidence and severity of some infections Hemilä 2006, pp. 5-9, 105-21.

In the early 20th century, Alfred Hess carried out extensive studies of scurvy and summarized a large series of autopsy findings as follows: “pneumonia, lobular or lobar, is one of the most frequent complications [of scurvy] and causes of death” and “secondary pneumonias, usually broncho-pneumonic in type, are of common occurrence, and in many [scurvy] epidemics constitute the prevailing cause of death”, see Hemilä H, 2007. In this journal, Hess 1932 commented that in “infantile scurvy … a lack of the antiscorbutic factor which leads to scurvy, at the same time predisposes to infections [particularly of the respiratory tract]. … Similar susceptibility to infections goes hand in hand with adult scurvy.” Thus, deficiency of vitamin C and pneumonia may be associated. Deficiency of vitamin C is not rare even nowadays Schleicher RL, 2009.

Furthermore, vitamin C has reduced the duration and severity of the common cold in well-nourished people suggesting that the vitamin may have effects on the respiratory system even in the absence of frank deficiency Hemilä H, 2013.

Hemilä H, 2013 carried out a Cochrane review and found 3 controlled trials that looked at whether vitamin C prevents pneumonia and 2 that looked at whether it might help in curing pneumonia. Each of the 5 studies found that vitamin C supplementation was significantly beneficial against pneumonia. Two of them were placebo-controlled RCTs.

Pitt HA, 1979 administered vitamin C to US marine recruits and reported 7 cases of pneumonia in the placebo-group compared with 1 case in the vitamin C group. Hunt C, 1994 administered vitamin C to elderly people who were admitted to hospital in the UK because of bronchopneumonia or acute exacerbation of chronic bronchitis. They reported a significant decrease in the “total respiratory score” by vitamin C administration, and 5 deaths in the placebo group compared with 1 death in the vitamin C group. Hunt et al. tested the effect of vitamin C “over and above those of normal medication (mainly antibiotics and cough medicines) to which all participants were exposed” so that all their patients received antibiotics and vitamin C was not an alternative to them.

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have a high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied, especially in pneumonia patients with low plasma vitamin C levels.