The upper level: examining the risk of excess micronutrient intake in pregnancy from antenatal supplements

Abstract

Micronutrient deficiencies are prevalent and co‐occurring among pregnant women in low‐ and middle‐income countries (LMIC). To prevent and treat deficiencies, antenatal vitamin and mineral supplements are the most common interventions during gestation. With most micronutrients, there can be health risks when intake regularly exceeds a high amount, and an upper threshold value set by the United States and Canada, the World Health Organization, and other groups is commonly called an upper intake level (UL). This review summarizes what is known about risks in pregnancy when ULs are exceeded and assesses the potential risk of exceeding the UL if a pregnant woman is taking a multiple micronutrient supplement. Overall, there is limited information on pregnancy‐specific risks from excess intake. When assuming high dietary intake plus the amount in a standard multiple micronutrient supplement (with 30 mg of iron), only niacin and iron would be expected to slightly exceed the UL. Known risks for this level intake for each nutrient are transient and mild.

Review of the evidence regarding the use of antenatal multiple micronutrient supplementation in low‐ and middle‐income countries

“…Gernand modeled the impact of supplementation with UNIMMAP on the micronutrient intakes of pregnant women consuming a nutrient‐rich, diverse diet that meets the dietary intake recommendations from both WHO and the Institute of Medicine and found very little risk of excessive intakes (i.e., exceeding the upper level (UL) of recommended nutrient intakes). When UNIMMAP was provided along with a nutrient‐rich diet, intakes of iron, niacin, and folic acid reached or slightly exceeded the UL; but these were unlikely to result in significant adverse effects . More detailed information on the risk of exceeding the UL with MMS can also be found in Gernand .…”

“…When UNIMMAP was provided along with a nutrient‐rich diet, intakes of iron, niacin, and folic acid reached or slightly exceeded the UL; but these were unlikely to result in significant adverse effects . More detailed information on the risk of exceeding the UL with MMS can also be found in Gernand . In regard to iron intake, the current WHO recommendation is 30–60 mg in pregnancy; however, the U.S. Institute of Medicine set the UL at 45 mg, suggesting that 30 mg may have a better safety margin than 60 mg…”

Setting research priorities on multiple micronutrient supplementation in pregnancy

“…Prenatal multiple micronutrient supplementation (MMS) provides a good solution to supply those essential nutrients. A series of publications recently put forward by the New York Academy of Sciences (NYAS) presented evidence of the benefits of MMS on maternal and perinatal outcomes (i.e., significant risk reduction of LBW, SGA, preterm birth, and stillbirth), in addition to those provided by iron and folic acid . These publications identify populations in low‐ and middle‐income countries (LMIC), where a switch to MMS would be justified, consistent with the WHO Antenatal Care Guidelines, and would be highly cost‐effective .…”

Benefits of supplementation with multiple micronutrients in pregnancy

“…A second paper published in the special issue addresses the question of whether multiple micronutrient consumption might lead to excess intakes of certain micronutrients . For many micronutrients, there may be health risks associated with regular intake that exceeds an upper threshold for safety, typically called an upper level (UL).…”

“…A second paper published in the special issue addresses the question of whether multiple micronutrient consumption might lead to excess intakes of certain micronutrients. 9 For many micronutrients, there may be health risks associated with regular intake that exceeds an upper threshold for safety, typically called an upper level (UL). To examine this question, the intake of each nutrient that would result from consuming the UNIMMAP formulation daily, on top of a diet that already included the recommended intake of that nutrient, was compared with the UL.…”