Ghosh Santu, Thomas Tinku, Pullakhandam Raghu, Nair Krishnapillai Madhavan, Sachdev Harshpal S, Kurpad Anura V
Department of Biostatistics, St John's Medical College, Bengaluru, India.
Drug Safety Division, National Institute of Nutrition, Indian Council of Medical Research, Hyderabad, India.
Eur J Clin Nutr. 2023 Apr;77(4):436-446. doi: 10.1038/s41430-022-01204-4. Epub 2022 Sep 8.
In 2006, the WHO published a framework for calculating the desired level of fortification of any micronutrient in any staple food vehicle, to reduce micronutrient malnutrition. This framework set the target median nutrient intake, of the population consuming the fortified food, at the 97.5th percentile of their nutrient requirement distribution; the Probability of Inadequacy (PIA) of the nutrient would then be 2.5%. We argue here that the targeted median nutrient intake should be at Estimated Average Requirement (50 percentile), since the intake distribution will then overlap the requirement distribution in a population that is in homeostasis, resulting in a PIA of 50%. It is also important to recognize that setting the target PIA at 2.5% may put a sizable proportion at risk of adverse consequences associated with exceeding the tolerable upper limit (TUL) of intake. This is a critical departure from the WHO framework. For a population with different age- and sex-groups, the pragmatic way to fix the fortification level for a staple food vehicle is by achieving a target PIA of 50% in the most deprived age- or sex-group of that population, subject to the condition that only a very small proportion of intakes exceed the TUL. The methods described here will aid precision in public health nutrition, to pragmatically determine the precise fortification level of a nutrient in a food vehicle, while balancing risks of inadequacy and excess intake.
2006年，世界卫生组织发布了一个框架，用于计算任何主食载体中任何微量营养素的理想强化水平，以减少微量营养素营养不良。该框架将食用强化食品人群的目标营养素摄入量中位数设定为其营养素需求分布的第97.5百分位数；此时该营养素的摄入不足概率（PIA）将为2.5%。我们在此认为，目标营养素摄入量中位数应设定为估计平均需求量（第50百分位数），因为在处于稳态的人群中，摄入量分布将与需求分布重叠，从而导致PIA为50%。还必须认识到，将目标PIA设定为2.5%可能会使相当大比例的人群面临与超过可耐受摄入量上限（TUL）相关的不良后果风险。这与世界卫生组织的框架有重大差异。对于一个具有不同年龄和性别人群的群体，确定主食载体强化水平的务实方法是在该群体中最贫困的年龄或性别组中实现50%的目标PIA，前提是只有极小比例的摄入量超过TUL。这里描述的方法将有助于提高公共卫生营养的精准度，在平衡摄入不足和过量摄入风险的同时，切实确定食品载体中营养素的精确强化水平。
