Non-Communicable Diseases Research Unit, South African Medical Research Council.
Division of Human Nutrition, Cape Town, South Africa.
Am J Clin Nutr. 2019 Jul 1;110(1):91-101. doi: 10.1093/ajcn/nqy382.
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.
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.
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.
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).
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.
在一些地区，多种维生素 A（VA）干预措施在同一目标人群中同时进行，这可能导致过度储存。视黄醇同位素稀释（RID）是一种比血清视黄醇更敏感的技术，可用于测量 VA 状态。
我们评估了生活在南非一个习惯性食用肝脏并接触 VA 补充剂和强化剂的地区的学龄前儿童在接受高剂量补充剂前后的 VA 状况。
在基线血样采集后，受试者（46.7±8.4 个月；n=94）接受 1.0 μmol[14,15]-13C2-视黄基乙酸酯，通过 RID 估计总肝视黄醇储备，随后进行 14 天的血样随访。通过频率问卷评估肝脏摄入量。根据当前实践，在 RID 测试后给予常规 200,000 IU VA 胶囊。RID 在 1 个月后重复进行。使用超高效液相色谱法评估血清视黄基酯。
在基线时，63.6%的儿童患有维生素 A 过多症，定义为总肝视黄醇储备≥1.0 μmol/g 肝，补充后增加到 71.6%（1.13±0.43 至 1.29±0.46 μmol/g；P<0.001）。补充前后，4.8%和 6.1%的儿童血清总 VA 以视黄基酯的形式升高。基线时摄入肝脏≥1/月（比值 3.70[95%CI：1.08,12.6]）和过去 12 个月内接受 2（4.28[1.03,17.9]）或 3（6.45[0.64,65.41]）种补充剂的儿童发生维生素 A 过多症的可能性更高。与基础值较低的儿童相比，在基础值最高四分位的儿童中，补充后全身储存量减少，而这些儿童的储存量增加（P=0.007）。
在像南非这样的队列中，儿童通过饮食摄入足够的 VA，VA 强化和补充重叠，应该重新评估学龄前儿童 VA 胶囊的分发。该试验在 https://clinicaltrials.gov/ct2/show/NCT02915731 注册为 NCT02915731。
