Vitamin A for diarrhea

Oral vitamin A every 4 months reduces deaths from diarrhea (by 28%) and measles (by 20%) in children ages 6 months to 5 years who aren’t getting enough vitamin A in their diet.

Photo Credits: Tran Thi Hoa

  

Why is vitamin A important? 

  • Vitamin A is an essential nutrient but it is not produced by our bodies. It is in some foods and supplements. Vitamin A is important for vision, red blood cell production, our immune system, and reproduction. People who don’t get enough vitamin A are at risk for health effects including dry eyes, stunting, anemia, and infections, such as measles. Vitamin A is low in diets that rely heavily on fruits and vegetables although you can get vitamin from these foods. 

What are sources of vitamin A 

Animal sources (such as meat and eggs) 
Vegetables (especially those orange or dark green in colour, such as sweet potato, carrots, lettuce, and spinach) 

Do vitamin A supplements work? 

  • In countries with high Vitamin A deficiency, supplements reduce the number of deaths in children between six months and five years and the number of cases of measles (measles incidence).    

Equity: does vitamin A supplementation work in the disadvantaged? 

  • Vitamin A deficiency is more common in developing countries. Vitamin A supplements reduce child deaths and measles among disadvantaged children In developing countries, many people can’t get enough vitamin A in their diet and need supplements. 

Intervention Delivery 

  • Vitamin A supplements can be given orally as capsules or liquid. 
  • The WHO recommends 50,000 IU for infants under 6 months, 100,000 IU for infants 6-12 months, and 200,000 IU for children over 12 months, provided every 4-6 months. Studies provided between 50,000 and 200,000 IU of vitamin A in a single dose, every 4 months, or every 6 months.  

Population and Setting 

  • 42 out of 43 included studies were conducted in low- and middle-income countries. 
  • All participants were healthy children. Those in hospital or with diseases were excluded.

Summary of Findings [SOF] Table: Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 

Patient or population: Children aged between 6 months and five years 
Settings: Children living in the community
Intervention: Vitamin A supplementation 
Comparison: Placebo or usual care 

Outcomes 

Anticipated absolute effects per year 

Relative effect 
(95% CI) 

No of Participants 
(studies) 

Quality of the evidence 
(GRADE) 

Risk without vitamin A supplementation (Control) 

Risk with vitamin A supplementation (95% CI) 

Mortality from any cause 

Follow up 12-96 weeks 

High risk population  

RR 0.76  
(0.69 to 0.83) 

194,795 
(17 studies) 

high 

9.0 per 100 

2.2 fewer deaths per 100 (1.5-2.8) 

 

Diarrhea related mortality 

High risk population 

RR 0.72  
(0.57 to 0.91) 

90,951 
(7 studies) 

moderate1 

0.9 per 100 

0.6 fewer deaths per 100 (0.4-0.8) 

Measles related mortality 

High risk population 

RR 0.80  
(0.51 to 1.24) 

88,261 
(5 studies) 

moderate 

0.44 per 100 

0.35 fewer deaths per 100 (0.2 fewer to 1.0 more) 

Side effect: Vomiting 

High risk population 

RR 2.75  
(1.81 to 4.19) 

2994 
(3 studies) 

low2, 3 

7.3 per 100 

12.7 more per 100 (1.3 fewer to 16 more) 
 

Adverse Events: Short term side effects identified in the review were vomiting and Fontanelle (soft spots on a baby’s head). An increase in vomiting was identified in three of the included studies. Fontanelle was also identified in three trials but only two trials had insufficient data. Most included studies included children over one year of age and therefore would not have looked for this side effect.  

 

Relevance of the review for disadvantaged communities 
Vitamin A supplements reduce child deaths and measles among disadvantaged children

Oral vitamin A every 4 months reduces deaths from diarrhea (by 28%) and measles (by 20%) in children ages 6 months to 5 years who aren’t getting enough vitamin A in their diet.

Findings 

Interpretation 

Equity – Which of the PROGRESS groups examined 

 

All but 1 (42 of 43) of the included studies reporting on mortality from any cause were conducted in developing countries 

Vitamin A deficiency tends to be higher in low and middle income countries and therefore may have greater effects in these settings. 

The review reported subgroup analyses for age and sex The average child was 30.5 months. The majority of included studies assigned approximately equal numbers of males and females.  

Differences in effectiveness for other subgroups have not been determined. For example, are supplements as effective among those in different places of residence, such as rural communities, or low-income urban communities or among families with lower income. 

 

The largest effects from vitamin A were found in the groups at highest risk for vitamin A deficiency. 

Depending on the availability of vitamin A rich foods within the local setting, the effects of vitamin A supplementation on all-cause mortality, cause-specific mortality, cause-specific morbidity, and vitamin A will differ. Locations with greater access to foods containing vitamin A may have smaller effects from vitamin A supplementation.  Populations with more vitamin A deficiency may have greater effects. The results of this review are likely applicable to any population with vitamin A deficiency. 

Equity Applicability 

 

The review does not report on the effectiveness of delivery mechanisms for vitamin A supplementation.  

  • The studies included in this review gave vitamin A supplementation orally, as capsules or liquid.  

  • All but one study provided vitamin A supplementation using the standard dose recommended by the WHO which is 50,000 IU for infants under 6 months, 100,000 IU for infants 6-12 months, and 200,000 IU for children over 12 months, provided every 4-6 months. The other study provided participants with a weekly dose of vitamin A supplementation for 52 weeks. 

Policy makers and practitioners will have to look at other study types to determine the most suitable delivery mechanism within the local setting. Future trials or programs may consider evaluating smaller but likely to be effective doses that may also reduce the risk of vomiting. Other than supplements, vitamin A can be delivered through food fortification, consumption of vitamin A rich foods, and beta-carotene supplements 

 

The review summarized findings based on studies in which the level of organization may be higher than what is available outside of research settings. 

Factors to consider when assessing whether the intervention effects are transferable to your settings include: 

  • The availability of data on who might benefit from the intervention (those who are vitamin A deficient) 

  • The financial and organizational resources to provide clinical and managerial support for vitamin A supplementation and to ensure distribution of properly stored and active supplements 

  • The supplies to deliver services 

The included studies only considered the effects of vitamin A supplementation on healthy children. Those in hospital or with diseases were excluded. 

The effects of vitamin A supplementation on children with disease or infection may need to be explored in other studies. 

Cost-equity 

 

The review did not report on the cost-effectiveness of vitamin A supplementation overall or in each disadvantaged group. However, the authors state that vitamin A supplementation may be among the most cost-effective public health interventions (p. 28). 

The cost of vitamin A supplementation may be variable based on local conditions outside of research settings. 

Monitoring & Evaluation for PROGRESS Groups 

 

There is sufficient evidence that vitamin A supplementation prevents mortality.  

Vitamin A supplementation is recommended for children under 5 in areas at risk for vitamin A deficiency.  

Implementation data, including the core components of an intervention, the degree of delivery of the intervention in practice, and factors influencing implementation (such as core components of the intervention, the degree to which they are delivered in practice, and aspects of the trial that may have influenced implementation), were underreported in the studies included in the review (p.27). The authors stress the importance of effective distribution and storage of supplements. 

Implementation of a vitamin A supplementation program needs to include an evaluation to ensure the effectiveness of the intervention. 

The review did not assess the role of co-interventions on effectiveness. Examples of co-interventions in included studies were vitamin  A and vitamin E supplements (7 studies), vitamin A and zinc supplementation (3 studies), vitamin A and measles vaccination (4 studies), vitamin A and both measles and polio vaccination (1 study), vitamin A supplementation for both infant and mother (1 study), and vitamin A and L-tetramisole (1 study).  

Other studies are needed for policy makers and practitioners to make decisions on how vitamin A might relate to other nutritional and health interventions.

Adverse Events:

Short term side effects identified in the review were vomiting and Fontanelle (soft spots on a baby’s head). An increase in vomiting was identified in three of the included studies. Fontanelle was also identified in three trials but only two trials had insufficient data. Most included studies included children over one year of age and therefore would not have looked for this side effect.  

 

Lives Saved with Vitamin A supplementation for preventing diarrhea in children 1-59 months old (using the Lives Saved Tool - LiST)

 

Country

Current Coverage

Lives Saved if coverage of intervention scaled up to 90%

Burden of Disease (DALYs 000s)

Bhutan

48%

2

                                8.0

Bolivia

24%

33

123.4

Burundi

73%

290

830.0

Cameroon

89%

25

1134.6

Cape Verde

0%

2

2.6

Central African Republic

0%

252

466.9

Chad

68%

614

1317.8

Comoros

18%

16

25.0

DR Congo

83%

848

8259.9

Egypt

68%

94

325.6

El Salvador

13%

3

24.9

Eritrea

44%

93

213.3

Ethiopia

84%

381

3021.2

Haiti

 

48

321.8

Lesotho

 

36

63.4

Somalia

 

635

1177.9

South Sudan

 

101

644.8

Uganda

 

595

1446.8

Zimbabwe

 

314

475.7

 

Who is this summary for? 

People making decisions about the use of vitamin A supplementation for children. 

This summary is based on the following systematic review: 

Imdad A, Herzer K, Mayo-Wilson E, Yakoob MY, Bhutta ZA. Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age. Cochrane Database of Systematic Reviews 2010, Issue 12. Art. No.: CD008524. DOI: 10.1002/14651858.CD008524.pub2. 

What is a systematic review? 

A summary of studies addressing a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise the relevant research, and to collect and analyse data from the included studies. 

This summary includes: 

  • Key findings from research based on one systematic review 
  • Considerations about the relevance of this research for low and middle income countries 
Not included: 
  • Recommendations 
  • Additional evidence not included in the summarized systematic review 
  • Detailed descriptions of the interventions or their implementation

AMSTAR Rating: 11/11

Comments on this summary? Please contact Jennifer Petkovic.