More ways to successfully supplement vitamin

Our attention was drawn to your recently published original research article titled “A micronutrient-fortified young-child formula improves the iron and vitamin D status of healthy young European children: a randomized, double-blind controlled trial” by Akkermans et al. (1). We compliment the authors on this publication and their commitment to these relevant public health issues. The authors studied hemoglobin, serum ferritin, and 25-hydroxyvitamin D concentrations in toddlers in relation to the consumption of a newly developed young-child formula. The formula is fortified with carbohydrates, fibers, nonheme iron, essential trace elements, vitamins, and folic acid; and the amounts of proteins and electrolytes in this formula are lower than in cow milk. During the study period, parents were asked not to change their child’s dietary habits, including the use of supplements. A minority of 30% of children received vitamin D supplements. So, in fact, 4 groups can be distinguished: those who drank cow milk with or without vitamin D supplementation and those who drank formula with or without supplementation. The authors report that the intake of the young-child formula resulted in increased concentrations of the biomarkers after 20 wk of consumption, whereas these decreased in the controls. The effect of vitamin D supplementation in this respect remains unclear. As a final remark, the authors state that a standard young children’s diet containing cow milk with or without vitamin D supplements is “insufficient for preventing [iron deficiency] and [vitamin D deficiency]” in toddlers and they conclude that the new product “preserves [iron] status and improves vitamin D status. ” The latter seems accurate, but we are not sure that adequate supplementation would not have equally improved the iron and vitamin D status (2, 3). An equally appropriate conclusion could have been to endorse the current national guideline for a healthy diet with a daily supplement of 10 lg vitamin D (4, 5). A comparison between the above-mentioned 4 groups could have provided us with the answer. Raw data, however, have not been made available with the open-access publication. Parents ignore the guideline on vitamin D supplementation on a large scale (1, 5). Yet, the dropout ratio during the formula intervention also was considerable, higher than the previously estimated 25%. This is remarkable because the young-child formula was available free of charge. This study merely seems to confirm the difficulties that are met when implementing healthy dietary habits during a toddler’s transition to table foods (6). This article certainly will not be the last reporting outcomes of this intervention. We hope that future conclusions will be better in tune with the European guidelines on toddlers’ nutrition. Long-term benefits of this well-conducted randomized, doubleblind, controlled trial on neurodevelopment and overall health are awaited and we expect that outcomes will include growth (7). We also are curious to learn about the effects of the increased carbohydrate and fiber content of the elevated trace element and vitamin amounts, and of the folic acid content, as well as the reductions in proteins and electrolytes.