Study: Vitamin C Benefits Offspring of Pregnant Smokers

May 26, 2014

Daily vitamin C may offer some protection to the respiratory health of infants whose mothers smoked during pregnancy, a newly published study reported.

[[{"type":"media","view_mode":"media_crop","fid":"24647","attributes":{"alt":"","class":"media-image media-image-right","id":"media_crop_5833041579462","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2179","media_crop_rotate":"0","media_crop_scale_h":"145","media_crop_scale_w":"150","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"line-height: 1.538em; float: right;","title":" ","typeof":"foaf:Image"}}]] Pregnant smokers who took vitamin C improved the respiratory health of infants, according to the results of a study published in JAMA. 

Newborns of pregnant smokers who took 500 mg/d of vitamin C had improved pulmonary function and were less likely to wheeze during the first year of life compared with the babies of pregnant smokers who did not take the supplement. In the study, 89 pregnant smokers received the vitamins, while 90 pregnant smokers were given a placebo. 

Pertinent Points

- Vitamin C taken
by pregnant smokers can improve the respiratory function of newborns.

- In addition, babies born to mothers who smoked throughout pregnancy but took the vitamin C supplement had decreased wheezing through the first year of life when compared with children born to smokers who did not take the supplement.

- Although more study is needed, vitamin C supplements could offer an inexpensive intervention, but smoking cessation should still be the goal..

Newborn pulmonary function was measured using the ratio of the time to peak tidal expiratory flow to expiratory time (TPTEF:TE). The results indicated that babies born to mothers who took vitamin C had a TPTEF:TE of 0.383 versus 0.345 for the control group (adjusted 95% CI for difference, 0.011-0.062; P=0.006)

There were, however, no significant differences in the 1-year pulmonary function test results between the vitamin C and placebo groups.

"Although smoking cessation is the foremost goal, most pregnant smokers continue to smoke, supporting the need for a pharmacologic intervention," the authors, led by Cindy T. McEvoy, MD, MCR, of Oregon Health & Science University, Portland, wrote.

The results point to an inexpensive and simple approach to try to help minimize the effects of smoking in pregnancy, the authors concluded, noting that additional study is needed.

An accompanying editorial, Graham L. Hall, PhD, of the University of Western Australia, West Perth, agreed that the findings offer a potential way to minimize the harmful effects of maternal smoking on infant respiratory health, but he emphasized that smoking cessation must remain the primary goal.

"By preventing her developing fetus and newborn infant from becoming exposed to tobacco smoke, a pregnant woman can do more for the respiratory health and overall health of her child than any amount of vitamin C may be able to accomplish,” wrote Hall.

ObGyn.netfirst reported on these results in May 2012, when pilot study findings were presented at the American Thoracic Society 2012 International Conference.