NEW DELHI: Higher vitamin B12 levels in parents before conception and higher red blood cell (RBC) folate concentrations in mothers after conception could be related to lower risk of birth defect, suggesting that nutritional status may play a role, a study has found.
The findings, published in the journal Annals of Internal Medicine, support the potential importance of both paternal and maternal nutrition during the periconceptional period and early pregnancy, researchers said.
The team, including researchers from the Children's Hospital of Fudan University in China, used the Shanghai Preconception Cohort to study 3,032 couples who provided blood samples within 4 months before conception and 17,765 women who were tested at 4 months' gestation or earlier.
Vitamin B12 and folate levels were measured and their relationship with birth defects examined. Birth defects were identified among live births, stillbirths, and pregnancies ending because of foetal abnormalities.
"With increasing vitamin B12 levels before conception for the mother and the father, the risk for birth defects decreased. For the mother, the reduction in birth defects continued up to the highest vitamin B12 level," the authors wrote.
"After conception, higher levels of the mother's RBC folate and vitamin B12 were generally linked to lower risk for birth defects," they said.
Folic acid is a synthetic form of vitamin B9, an essential nutrient important for the body to make DNA, grow cells and produce RBCs. A deficiency can increase risk of neural tube (nervous system) defects in the infant, and supplementation is a standard of care for the mother before conception and during pregnancy.
Vitamin B12 has an important role in metabolism, and adequate levels may also reduce the risk for birth defects, the researchers said.
They added that most studies have focused on the mother, but the father's folic acid and vitamin B12 deficiencies around the time of conception may also increase the risk for birth defects.
The team studied both the mother's and the father's levels of RBC folate and vitamin B12 in the four months before conception -- low levels may affect the infant's genes and increase the risk for all types of birth defects that occur after conception or birth, they said. Follow-up for birth defects continued for up to one year.
The findings offer new insights into the risk for birth defects associated with vitamin B12 deficiency in the four months prior to conception, not only for the mother but also for the father, the researchers said.
Mothers should still supplement with folic acid before and after conception, but supplementation with vitamin B12 after conception may also be needed to reduce the risk for birth defects, they said.
The team added it is important to review any vitamin supplementation with a clinician.