Researchers from the University of Oxford, Queen Mary and the University of London have concluded the month of birth plays an important role in function of the immune system, particularly as it relates to the development of multiple sclerosis (MS). It is estimated that about 100,000 people in the United Kingdom suffer from the condition, which disables the neurological system as the immune system attacks the central nervous system. In addition to the connection between birth date and immune system function, researchers also reported vitamin D levels also corresponded to birth date.
Multiple sclerosis (MS) is an immune system disease resulting from a constant attack on the central nervous system by the immune system. Over time, the immune system attack causes interference between messages from the brain intended for other parts of the body. Muscle control, vision, memory and hearing are all affected by MS. In previous studies researchers have hypothesized that MS is caused by a combination of environmental and genetic factors. This study claims the environmental factor may be month of birth.
In England, the month in which an infant is born is associated with a specific risk factor for developing MS. May is the peak month with the majority of MS cases being diagnosed in people born in May. November accounts for the lowest risk factor for developing MS.
Researchers collected cord blood samples from 50 infants born in May and 50 infants born in November. The samples were tested for auto-reactive T cells and vitamin D. May infants measured lower levels of vitamin D and higher levels of auto-reactive T cells. November infants measured the opposite.
Researchers believe vitamin D supplementation studies are in order to test the effectiveness of vitamin D supplementation on cord blood levels and, possibly, MS rates. If vitamin D is to blame for the increased number of MS cases in May, supplementing the vitamin could help reduce risk. However, vitamin D is not the only factor in play. Increased levels of auto-reactive T cells in May could also play a part in the increased risk of MS. Additional research is needed to verify, reproduce and detail the connections between MS, vitamin D and auto-reactive T cells.
Source: Giulio Disanto, MD; Corey T. Watson, PhD; Ute C. Meier, DPhil; George C. Ebers, MD; Gavin Giovannoni, MD; Sreeram V. Ramagopalan, DPhil. Month of Birth and Thymic Output. JAMA Neurol. 2013;70(4):527-528. doi:10.1001/jamaneurol.2013.2116.