A review of the status of magnesium and related minerals in the sudden infant death syndrome (SIDS)

Sudden infant death syndrome (SIDS) is the sudden death of an infant under 1 year of age that remains unexplained after a thorough case investigation, including performance of a complete autopsy. Despite recent reductions in the SIDS rate attributed to placing the baby to sleep on his back, SIDS rem ains the most common cause of infant mortality between 1 month and 1 year o f age in developed countries. This review concerns the current state of a h ypothesis (1972) that magnesium deficiency, which causes sudden death in yo ung mammals, is the major cause of SIDS. Numerous investigators have compar ed the concentration of magnesium, and other minerals from soft tissues and bone in SIDS with non-SIDS controls (normal infants who died suddenly of k nown cause such as trauma). Because of rapid shifts of minerals during earl y development, SIDS and control infants must be matched for gestational and postnatal age. About 95 per cent of SIDS occurs between 1-6 months of life , with peak incidence at 2-4 months, when vitreous magnesium is high. There is little change in magnesium in the relatively inert vitreous despite ext remes in dietary magnesium. All values fall within a small range, with scat ter. Magnesium rapidly increases in foetal cartilage with ossification of t he bone. Early in magnesium deficiency, liver magnesium may be increased or unchanged, but it does not increase during magnesium excess. Lead accumula tion is increased in magnesium deficiency. Among infants with high environm ental exposure to lead, those who die of SIDS rather than non-SIDS infants have the greater lead burden. Soft water with low magnesium and calcium and with high concentration of sodium have been linked to higher SIDS rates, w hich have been attributed to low magnesium. It is concluded that the SIDS h ypothesis has neither been proved nor disproved.