South African preschool children habitually consuming sheep liver and exposed to vitamin A supplementation and fortification have hypervitaminotic A liver stores: a cohort study

Abstract

Background In some regions, multiple vitamin A (VA) interventions occur in the same target groups, which may lead to excessive stores. Retinol isotope dilution (RID) is a more sensitive technique than serum retinol to measure VA status. Objective We evaluated VA status before and after a high-dose supplement in preschool children living in a region in South Africa with habitual liver consumption and exposed to VA supplementation and fortification. Methods After baseline blood samples, subjects (46.7 ± 8.4 mo; n = 94) were administered 1.0 μmol [14,15]-13C2-retinyl acetate to estimate total liver retinol reserves by RID with a follow-up 14-d blood sample. Liver intake was assessed with a frequency questionnaire. In line with current practice, a routine 200,000 IU VA capsule was administered after the RID test. RID was repeated 1 mo later. Serum retinyl esters were evaluated using ultra-performance liquid chromatography. Results At baseline, 63.6% of these children had hypervitaminosis A defined as total liver retinol reserves ≥1.0 μmol/g liver, which increased to 71.6% after supplementation (1.13 ± 0.43 to 1.29 ± 0.46 μmol/g; P < 0.001). Total serum VA as retinyl esters was elevated in 4.8% and 6.1% of children before and after supplementation. The odds of having hypervitaminosis A at baseline were higher in children consuming liver ≥1/mo (ratio 3.70 [95% CI: 1.08, 12.6]) and in children receiving 2 (4.28 [1.03, 17.9]) or 3 (6.45 [0.64, 65.41]) supplements in the past 12 mo. Total body stores decreased after the supplement in children in the highest quartile at baseline compared with children with lower stores, who showed an increase (P = 0.007). Conclusions In children, such as this cohort in South Africa, with adequate VA intake through diet, and overlapping VA fortification and supplementation, preschool VA capsule distribution should be re-evaluated. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT02915731 as NCT02915731.

Liver is widely eaten by preschool children in the Northern Cape province of South Africa: Implications for routine vitamin A supplementation

“…Liver is an extremely rich source of preformed vitamin A, with lamb's liver containing 7,806 µg RE/100 g, according to the South African Food Composition Database (SAFOODS, ). Results of the recently analysed content of sheep livers procured in the Hantam area of Namakwa district showed the vitamin A content to be even higher, at a mean of 11,040 µg RE/100 g, and ranging from 6,308 to as high as 15,200 µg RE/100 g (van Stuijvenberg et al, ). The livers of older animals contained more vitamin A than the livers of the younger animals.…”

“…The literature suggests that high‐dose vitamin A supplementation can be phased out once <5% of the population younger than 5 years has serum retinol values <0.7 μmol/L and when there is proof of dietary adequacy in terms of vitamin A (Palmer, West, Dalmiya, & Schultink, ; West, Sommer, Palmer, Schultink, & Habicht, ; Wirth et al, ). In the Northern Cape province, we demonstrated not only low prevalence of vitamin A deficiency in terms of serum retinol in two separate communities in two separate districts where liver is eaten (Faber et al, ; van Stuijvenberg et al, ) but, more recently, also hypervitaminosis A in one of the communities (van Stuijvenberg et al, ). Furthermore, the present study shows that liver is eaten at a frequency sufficient to ensure adequate intake of vitamin A through the diet in all districts of this province.…”

“…Weight was measured to the nearest 0.05 kg using an electronic load cell scale; again, the same model (UC‐321 Personal Precision Health Scale, A&D Company) was used in all subdistricts. All measurements were taken following standard procedures (van Stuijvenberg et al, ). Z ‐scores were calculated using the 2006 WHO growth standards (World Health Organization, ).…”

Is it time for South Africa to end the routine high-dose vitamin A supplementation programme?

“…A recent SA study conducted in Northern Cape Province, where liver is frequently eaten, measured liver vitamin A stores (using retinol isotope dilution) before and after a high-dose supplement in preschool children who consumed liver regularly and were exposed to VAS and fortification. [29] It showed that 64% had hypervitaminosis A at baseline, which increased to 72% after VAS, while no children had vitamin A-deficient liver stores. Liver vitamin A concentrations correlated significantly with the number of vitamin A supplements received during the past year, as well as the total number of vitamin A supplements received since birth.…”

“…Liver vitamin A concentrations correlated significantly with the number of vitamin A supplements received during the past year, as well as the total number of vitamin A supplements received since birth. [29]…”