Effects of maternal B12 supplementation on neurophysiological outcomes in children: a study protocol for an extended follow-up from a placebo randomised control trial in Bangalore, India

The impact of socioeconomic and stimulus inequality on human brain physiology

The brain undergoes profound structural and dynamical alteration in response to its stimulus environment. In animal studies, enriched stimulus environments result in numerous structural and dynamical changes along with cognitive enhancements. In human society factors such as education, travel, cell phones and motorized transport dramatically expand the rate and complexity of stimulus experience but diverge in access based on income. Correspondingly, poverty is associated with significant structural and dynamical differences in the brain, but it is unknown how this relates to disparity in stimulus access. Here we studied consumption of major stimulus factors along with measurement of brain signals using EEG in 402 people in India across an income range of $0.82 to $410/day. We show that the complexity of the EEG signal scaled logarithmically with overall stimulus consumption and income and linearly with education and travel. In contrast phone use jumped up at a threshold of $30/day corresponding to a similar jump in key spectral parameters that reflect the signal energy. Our results suggest that key aspects of brain physiology increase in lockstep with stimulus consumption and that we have not fully appreciated the profound way that stimulus expanding aspects of modern life are changing our brain physiology.

Vitamin D3 and B12 supplementation in pregnancy

AIM

To assess the efficacy of vitamin D3 or B12 supplementation during pregnancy.

METHODS

Pregnant women at 6-14 weeks in the intervention arm received oral high dose intermittent vitamin D3 and/or low dose B12 supplementation if they had vitamin D or vitamin B12 deficiency. The control arm received prescribed dietary instruction only. An additional observational arm for those mothers at booking with normal vitamin D and vitamin B12 level was also recruited. All groups received standard care during pregnancy.

RESULTS

The primary endpoint of either vitamin D or B12 at term was not met. At baseline 25% participants in both the interventional and control arms had severe D deficiency (<30 nmol/l), reducing to under 3.4% in both groups. No maternal differences in vitamin D or B12 levels were found at delivery between the intervention, control, or observational groups. No significant difference in any of the pregnancy or birth outcomes was observed between three groups.

CONCLUSIONS

In this study, oral supplementation of high dose intermittent vitamin D or low dose vitamin B12 regime failed to correct the relevant nutritional deficiencies in Bangladeshi pregnant women as per protocol. Both dietary supplementation and high dose vitamin D corrected severe vitamin deficiency.

Vitamin B-12 Supplementation during Pregnancy and Early Lactation Does Not Affect Neurophysiologic Outcomes in Children Aged 6 Years

BACKGROUND

Deficiency of vitamin B-12 is common in pregnant Indian women. Assessment of neurophysiological measures using event-related potentials (ERPs) may yield additional information on the effects of maternal B-12 supplementation on child brain function.

OBJECTIVES

The objective of the study was to evaluate the effects of vitamin B-12 supplementation (50 μg daily orally) during pregnancy on the childhood ERP measures of positive waveform ∼300 ms after stimulus (P300) and mismatch negativity.

METHODS

This study was a follow-up of children born to pregnant women who received oral vitamin B-12 supplements (n = 62) compared with children of pregnant women who received placebo (n = 70) from a randomized controlled trial. The mean ± SD child age was 72 ± 1 mo. We used the Enobio system to assess the ERP measures P300 and mismatch negativity.

RESULTS

There were no significant differences in the primary outcomes, amplitudes, and latencies of the P300 results and the mismatch negativity between children in the supplementation and placebo groups. We combined the intervention and placebo groups for secondary analyses. On multiple variable regression analysis after adjusting for treatment group, intrauterine growth restriction, and home environment, P300 amplitude in children was significantly higher in the lowest tertile of third-trimester maternal methylmalonic acid (MMA) concentrations (β = 3034.04; 95% CI: 923.24, 5144.83) compared with the highest MMA tertile (β = 1612.12; 95% CI: -258.86, 3483.10, P = 0.005).

CONCLUSIONS

While no significant effects of maternal vitamin B-12 supplementation on children's ERP measures were seen at 72 mo, elevated maternal MMA concentrations in the third trimester were negatively associated with P300 amplitude in children. It may be worthwhile to study the impact of maternal and infant vitamin B-12 supplementation on childhood brain structure and function in longer and larger trials. The parent trial was registered at clinicaltrials.gov as NCT00641862.