Vitamin A supplementation in northern Ghana: effects on clinic attendances, hospital admissions, and child mortality

Ross, David A.; Dollimore, Nicola; Smith, P. G.; Kirkwood, Betty; Arthur, Paul; Morris, Saul S.; Addy, H.A.; Binka, F. N.; Gyapong, John; Tomkins, Andrew

doi:10.1016/0140-6736(93)91879-q

Cited by 307 publications

(35 citation statements)

References 23 publications

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“…For example, deficiency in vitamin A drastically increases the mortality rate from measles (10) and the incidence of diarrhea (11). Moreover, supplementation in vitamin A or retinol reduces measles-related mortality and diarrhea in children (36, 37). Until now, the direct effect of RA on B cell function in protection against infection was unknown.…”

Section: Discussionmentioning

confidence: 99%

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response

et al. 2016

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Retinoic acid (RA) plays an important role in the balance of inflammation and tolerance in T cells. Furthermore, it has been demonstrated that RA facilitates IgA isotype switching in B cells in vivo. However, it is unclear whether RA has a direct effect on T-independent B cell responses in vivo. To address this question, we generated a mouse model where RA signaling is specifically silenced in the B cell lineage. This was achieved through the overexpression of a dominant negative receptor α for RA (dnRARα) in the B cell lineage. In this model, we found a dramatic reduction in marginal zone (MZ) B cells and accumulation of transitional 2 B cells in the spleen. We also observed a reduction in B1 B cells in the peritoneum with a defect in the T-independent B cell response against 2,4,6-trinitrophenyl. This was not a result of inhibited development of B cells in the bone marrow, but likely the result of both defective expression of S1P1 in MZ B cells and a defect in the development of MZ and B1 B cells. This suggests that RARα expression in B cells is important for B cell frequency in the MZ and peritoneum, which is crucial for the generation of T-independent humoral responses.

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Section: Discussionmentioning

confidence: 99%

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response

et al. 2016

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“…Antibiotics [8], probiotics [9], glutamine supplementation [10] and long chain fatty acid supplements [11] have been tried without success. Multiple micronutrient (MM) supplementation is an attractive potential therapy as micronutrients such as zinc [12,13] and vitamin A [14] have previously been shown to reduce morbidity and mortality from infectious diarrhoeal illnesses, hinting at an immunological role in the intestine. Furthermore, populations in which EE is prevalent also have a high prevalence of micronutrient deficiencies, which is also seen in HIV positive individuals.…”

Section: Introductionmentioning

confidence: 99%

High dose multiple micronutrient supplementation improves villous morphology in environmental enteropathy without HIV enteropathy: results from a double-blind randomised placebo controlled trial in Zambian adults

et al. 2014

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BackgroundEnvironmental enteropathy (EE) is an asymptomatic abnormality of small bowel structure and function, which may underlie vaccine inefficacy in the developing world. HIV infection co-exists in many of these populations. There is currently no effective treatment. We conducted a secondary analysis of a randomised controlled trial of high dose multiple micronutrient (MM) supplementation on small bowel architecture in EE in participants with or without HIV infection.MethodsIn a double-blind parallel-group trial of the effect of MM on innate immune responses to oral vaccines, consenting Zambian adults were randomised to receive 6 weeks of 24 micronutrients as a daily capsule or placebo. HIV status was established after randomisation. Proximal jejunal biopsies were obtained after the supplementation period. Villous height, crypt depth, villous width, villous perimeter per 100 μm muscularis mucosa (a measure of epithelial surface area), and villous cross sectional area per 100 μm muscularis mucosa (a measure of villous compartment volume) were measured in orientated biopsy sections using semi-automated image analysis. Analysis was by intention to treat.Results18 patients received MM and 20 placebo. 6/18 MM and 9/20 placebo patients had HIV. In HIV negative patients given MM compared to placebo, mean villous height was 24.0% greater (293.3 v. 236.6 μm; 95% CI of difference 17.7–95.9 μm; P = 0.006), mean villous area was 27.6% greater (27623 v. 21650 μm2/100 μm; 95% CI of difference 818–11130 μm2/100 μm; P = 0.03), and median villous perimeter was 29.7% greater (355.0 v. 273.7 μm/100 μm; 95% CI of difference 16.3–146.2 μm/100 μm; P = 0.003). There was no significant effect on crypt depth or villous width. No effect was observed in HIV positive patients. There were no adverse events attributable to MM.ConclusionsMM improved small bowel villous height and absorptive area, but not crypt depth, in adults with EE without HIV. Nutritional intervention may therefore selectively influence villous compartment remodelling. In this small study, there was a clear difference in response depending on HIV status, suggesting that EE with superimposed HIV enteropathy may be a distinct pathophysiological condition.

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“…[1][2][3][4][5] Vitamin A supplementation of mothers after delivery improves the vitamin A status of both the mother and her breastfed infant.6 Sustainable, cost-effective methods forvitamin A capsule supplementation of both children and mothers in the developing world are needed.…”

Section: Introductionmentioning

confidence: 99%

Vitamin A capsule supplementation in Malawi villages: missed opportunities and possible interventions.

Berger

Courtright²,

Barrows³

1995

Am J Public Health

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A population-based survey was used to assess childhood and maternal vitamin A capsule coverage in Malawi and to investigate missed opportunities for capsule distribution. Overall, 9.3% of children had received vitamin A supplementation in the previous 6 months. Missed opportunities for receiving vitamin A were high in younger children. Fifty-five percent of mothers were covered in 8 villages served by volunteers and 23% in the 58 villages without volunteers. Existing strategies need to be redesigned and new strategies defined. For instance, mothers could receive supplementation during infant BCG vaccination, and children could receive initial supplementation during measles vaccination. Village health volunteers could be used to target children over 2 years of age.

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Vitamin A supplementation in northern Ghana: effects on clinic attendances, hospital admissions, and child mortality

Cited by 307 publications

References 23 publications

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response

High dose multiple micronutrient supplementation improves villous morphology in environmental enteropathy without HIV enteropathy: results from a double-blind randomised placebo controlled trial in Zambian adults

Vitamin A capsule supplementation in Malawi villages: missed opportunities and possible interventions.

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