Under the national nutrivigilance scheme, reports of adverse effects likely to be associated with the consumption of food supplements containing melatonin have been brought to the attention of ANSES. A retrospective analysis of these reports, combined with the considerable level of consumption of this type of supplement, led ANSES to conduct an assessment of the potential health risks. In its Opinion of February 2018, the Agency highlighted the existence of populations and situations at risk, for which the consumption of melatonin in the form of a food supplement should be avoided or medical advice should be sought. This mainly concerns pregnant and breastfeeding women, children and adolescents, people suffering from inflammatory or autoimmune diseases, people with epilepsy, asthma, or suffering from mood, behaviour or personality disorders, as well as anyone being treated with medication. People carrying out any activity requiring sustained vigilance where drowsiness could pose a safety problem should also avoid its consumption.

Cases of neonatal hypercalcaemia and congenital hypothyroidism involving food supplements for pregnant women have been reported to ANSES, under its national nutrivigilance scheme. These reports led the Agency to assess the risks associated with the consumption of food supplements containing vitamin D or iodine, intended for pregnant women. Having completed its expert appraisal, the Agency warns consumers against combining multiple sources of vitamins and minerals, in the absence of an identified need. It especially wishes to alert healthcare professionals of the importance of not combining sources of vitamins and minerals without regular biological monitoring. The Agency also reminds pregnant women that they should not consume food supplements without first seeking the advice of a healthcare professional.