The month in which a baby is born can affect the baby’s immune system and pre-determine the risk for multiple sclerosis.
Blood samples were taken from the umbilical cord of babies born in November and those born in May in a London study.
The blood was analysed to measure levels of vitamin D and levels of autoreactive T-cells.
T-cells are white blood cells which play a crucial role in the body’s immune response by identifying and destroying infectious agents, such as viruses.
However some T-cells are ‘autoreactive’ and capable of attacking the body’s own cells, triggering autoimmune diseases, and should be eliminated by the immune system during its development.
The results showed that the May babies had significantly lower levels of vitamin D – around 20 per cent lower than those born in November.
They also had about double the level of harmful autoreactive T-cells compared to the November babies.
Scientists at Queen Mary, University of London and the University of Oxford believe their findings provide a potential biological basis for why the month of birth can influence the development of multiple sclerosis (MS)
MS is a disabling neurological condition which results from the body’s own immune system damaging the central nervous system.
This interferes with the transmission of messages between the brain and other parts of the body.
It leads to problems with vision, muscle control, hearing and memory.
The development of MS is believed to be a result of a complex interaction between genes and the environment.
As vitamin D is formed by the skin when it is exposed to sunlight, the ‘month of birth’ effect has been interpreted as evidence of a prenatal role for vitamin D in MS risk.
The research is published in the journal Jama Neurology