Severe neonatal hypercalcemia related to maternal exposure to nutritional supplement containing Spirulina

Abstract

Spirulina platensis (Norst.) Geitler is a microalgae widely harvested in Asia, Africa and South America and used for centuries in these countries as a natural medicine and a nutritional complement. Indeed, this cyanobacterium could exert antioxidant, anti-inflammatory, anti-infective, hypolipidemic and anticancer properties [1–3]. It could also represent a nutritional supplement in developing countries, as it contains important quantities of proteins, minerals, B complex and liposoluble vitamins, particularly vitamin D [1]. In developed countries, nutritional supplements containing S. platensis are increasingly used and sold over the counter. They represent a “natural”, “ethnic” and “obviously safe”medication. Pregnant women are particularly exposed to these supplements. We here report a case of severe neonatal hypercalcemia related to an excessive maternal exposure to S. platensis. In April, 2010, a neonate was hospitalised the first day of his live in our university hospital for generalised seizures. His parents had no medical antecedent, there was no consanguinity, pregnancy was normal and the neonate was eutrophic with no malformation. Serum calcium was increased to 3.10 mmol/L (normal 10 ng/ml) and calcitriol (1,25dihydroxycholecalciferol) was greatly increased (260 pg/ml, normal 18–60 pg/ml). In the mother’s serum, 25hydroxycholecalciferol was normal (28 ng/ml) but calcitriol was increased (125 pg/ml, i.e. twice normal). Questioning revealed exposure to vitamin D supplementation at the beginning of pregnancy, and then daily exposure to S. platensis from the fourth month of pregnancy. S. platensisrelated maternal intoxication with 25-hydroxycholecalciferol hydroxylated to calcitriol by the placental 1α-hydroxylase is suspected to be responsible for foetal hypercalcemia. Causality assessment was scored “likely” according to the World Health Organisation Uppsala Monitoring Centre (WHO-UMC) criteria [4]. The safety of nutritional supplements containing S. platensis is poorly evaluated. The supplements seem to contain low levels of algal toxins, particularly microcystins (hepatotoxins), but S. platensis decreases in vitro hepatocyte viability [5]. Anatoxins (neurotoxins) have been detected in some S. platensis preparations [6]. No human S. platensis-induced hepatitis or neurological disease has been reported to our knowledge. Sparse S. platensis-related G. Moulis (*) :A. Batz :G. Durrieu : J.-L. Montastruc Service de Pharmacologie Clinique, Faculte de Medecine, Centre Midi-Pyrenees de Pharmacovigilance, de Pharmacoepidemiologie et d’Informations sur le Medicament, Unite INSERM U 1027, Centre Hospitalier Universitaire de Toulouse, Universite de Toulouse, 37 Allees Jules-Guesde, 31000 Toulouse, France e-mail: gmoulis@hotmail.com