Assessing the potential of milk iodine intake to mitigate iodine deficiency in pregnant women of the United States via supplementation of Ascophyllum nodosum meal to dairy cows: A sensitivity analysis

摘要

The brown seaweed Ascophyllum nodosum is knownto bioaccumulate iodine (I). Previous research showeda linear relationship between A. nodosum meal (ASCO)intake and milk I concentration in dairy cows. Thus,improving milk I concentration by supplementationof ASCO to dairy cows may be a compelling strategyto naturally boost I intake in humans. A sensitivityanalysis was conducted to gain insights regarding howdifferent milk I intakes affect the I status of pregnantwomen relative to the United States Institute of Medicine(US IOM) recommended dietary allowance (RDA;220 μg/d) and the World Health Organization (WHO)recommended nutrient intake (RNI; 250 μg/d) forI. Four studies in which dairy cows received variousamounts of ASCO generated the milk I data set usedin the sensitivity analysis. The annual per capita consumptionof 2% reduced-fat milk in the United States,converted to daily intake (i.e., 0.26 cup; 1 cup = 236.6mL), was used as the actual milk intake in the simulations.Five additional milk intake scenarios (2, 3, 4, and5 times the actual per capita milk consumption and the3 cups-equivalent recommended by the 2015–2020 DietaryGuidelines for American were also included in thesensitivity analysis with varying milk I concentrations(180, 765, and 483 μg/L). The 180, 765, and 483 μg/Lvalues are milk I concentrations derived from cows notreceiving ASCO or fed various amounts of ASCO inthe diet or a single level (113 g/d) during the grazingseason, respectively. With the actual United Statesmilk per capita consumption of 0.26 cup/d and milk Iconcentrations of 180, 765, and 483 μg/L, 5.09, 21.7,and 13.6% of the RDA for I for pregnant women weremet based on the US IOM, respectively. Similarly, 4.48,19, and 12% of the RNI for I advised by the WHO wasachieved with intake of 0.26 cup/d of milk containing Iconcentrations of 180, 765, and 483 μg/L, respectively.When 3 cups/d was included in the simulations, 58.2,247, and 156% (US IOM), and 51.2, 217, and 137%(WHO) of the RDA or RNI for I required by gestatingwomen was satisfied with milk I concentrations of 180,765, and 483 μg/L, respectively. A regression analysisbetween I intake and milk I concentration revealed that103 g/d of ASCO in the diet of dairy cows reached themaximum 500 μg/L threshold of I in milk recommendedby the European Food Society Authority. Overall, milkfrom dairy cows fed ASCO can prevent I deficiencyin pregnant women, but the amount of ASCO fed tocows needs to be fine-tuned to avoid excess I in milk.Further research is required to better understand theinteractions between goitrogenic compounds from foragesand concentrates and milk I concentration in cowsfed ASCO. Research to evaluate the concentration of Iin retail organic milk should be also conducted becauseof the high prevalence of ASCO fed in organic dairiesin the United States.