Marc Sorenson, EdD
An excellent scientific paper regarding the incidence of vitamin D deficiency in breastfeeding women was recently published in the journal Nutrients. The research was particularly interesting in that the investigators measured the serum vitamin D levels in breastfeeding mothers from three different geographic areas: Shanghai, China: Cincinnati, Ohio; Mexico City, Mexico. Their infants were also measured for vitamin D. Although there was considerable variance in D deficiency among the three areas, a large number of mothers and their offspring were deficient. The factors that closely related to deficiency were obesity, season and site. Among the infants, predictors of higher vitamin D status were formula feeding [probably with added vitamin D] and higher sunlight index.
The authors concluded “vD deficiency appears to be a global problem in mothers and infants, though the prevalence in diverse populations may depend upon sun exposure behaviors and vD supplementation. Greater attention to maternal and infant vD status starting during pregnancy is warranted worldwide.”
It is critically important that pregnant mothers be vitamin D replete during their entire pregnancies, because the fetus depends on the mother as the only source of nutrients, including vitamin D. For example, if infants are born to vitamin D deficient mothers, they may have such maladies as craniotabes, a softening of the skull that is a predictor of full-blown rickets. Heart failure is also possible among infants who are born severely deficient in vitamin D. As an example, in a study conducted in southeast England, sixteen infants were identified that had suffered heart failure and hypocalcaemia between 2000 and 2006. Six were of Indian and ten of African ethnicity. Six of them suffered cardiac arrest, three died, eight were placed on lung machines, and two were referred for heart transplants. The average serum vitamin D level of these children was only 7.4 ng/ml, and some of the infants had undetectable levels. Hypocalcaemia is usually caused by insufficient vitamin D in the blood and often results in convulsions and death, but the care givers had not even tried to assure that vitamin D levels were adequate. The researchers concluded with this statement: “Vitamin D deficiency and consequent hypocalcaemia are seen in association with severe and life-threatening infant heart failure. That no infant or mother was receiving the recommended vitamin supplementation highlights the need for adequate provision of vitamin D to ethnic minority populations.”
Many other diseases of the bones, brain and intellect in infants are related to deficiency of sunlight and vitamin D deficiency in their mother’s pregnancy. Sunlight exposure, of course, is the most natural method to obtain vast quantities of vitamin D. And with sunlight, we also obtain nitric oxide, endorphins and serotonin in addition to other photoproducts. Vitamin D is only one important product of sunlight exposure, and if we use only supplementation, we miss out on other important health benefits that supplementation does not provide.
 Jessica G. Woo, Yong-Mei Peng, Guillermo M. Ruiz-Palacios, Maria de Lourdes Guerrero and Ardythe L. Morrow. Sun Exposure and Vitamin D Supplementation in Relation to Vitamin D Status of Breastfeeding Mothers and Infants in the Global Exploration of Human Milk Study.
 Yorifuji J. et al. Craniotabes in normal newborns: the earliest sign of subclinical vitamin D deficiency. J Clin Endocrinol Metab 2008 [Epub].
 Maiya, S. et al. Hypocalcaemia and vitamin D deficiency: an important, but preventable cause of life-threatening heart failure. Heart 2008;94:581-84.