Vitamin D and Breastfeeding

The New Mexico Breastfeeding Task Force shares the concern of many in the breastfeeding community about the new guidelines for Vitamin D intake from the American Academy of Pediatrics (AAP).(1) These guidelines suggest that all infants, including exclusively breastfed infants, be supplemented with 200 IU of vitamin D daily. Of course infant formula is presently fortified with at least 400 IU of vitamin D/liter, so the issue devolves to a recommendation to supplement breastfed babies with vitamin D. Just as it has been shown that commercial discharge packs are an adverse influence on breastfeeding(2,3), there is an analogous concern that this new recommendation may similarly affect decisions to breastfeed. An inference that some vulnerable mothers may make from this recommendation--that breastmilk is in some way inferior or incomplete--may be enough to discourage their resolve to breastfeed in the first place, or may result in either breastfeeding failures or a shortening of the length of time of breastfeeding. The AAP guidelines have been published because of recent case reports of nutritional rickets in the United States. (4,10,11)     An additional dilemma is created by the recommendation from the medical community to avoid sunlight because of the increasing risk of skin cancer. However, if the new recommendation dissuades significant numbers of women from breastfeeding, we worry that the health consequences may far outweigh the benefits of this recommendation.

Nutritional rickets remains a worldwide problem and ranks in the top 5 of childhood killers in the developing world. Paradoxically, it is notably common in tropical countries where sunlight is abundant. In 1999 an important study described a group of 123 Nigerian children with rickets who were shown to have had a better response to treatment with calcium, or with calcium and vitamin D, than with vitamin D alone.(5)   After 24 weeks of therapy, 61% of the first group, 58% of the second, and only 19% of the third had achieved normal alkaline phosphatase levels and had radiographic evidence of nearly complete healing. Prior to beginning the study, all three groups were shown to have had low intakes of calcium. Children in much of the developing world are known to have similar low calcium intakes, and the enigma of rickets in the sunny tropics is thus nicely explained. Dietary calcium deficiency has now been shown to be important in the development of nutritional rickets here in the United States as well. A recent retrospective review from Yale of 43 children with nutritional rickets found that the majority (86%) had been weaned to diets with minimal dairy content and only 22% had low levels of serum 25OH vitamin D.(6)

In an additional effort to explain the prevalence of rickets in sunny environments, the statement has often been made that "[d]arkly pigmented children are singularly susceptible to rickets."(7e.g.)   The AAP statement says that "[t]he effects of sunlight exposure on vitamin D synthesis are also decreased in individuals with darker skin…" While the latter statement is strictly true, one must not conflate it with the former, which does not seem to be evidence based. The reference cited in the AAP recommendation says that "dark skinned individuals may require up to 6 times the exposure to UVB radiation as required by light skinned individuals to maintain adequate levels of serum vitamin D."(8) This statement comes in turn from a reference that goes on to say that…"skin pigmentation does not affect the amount of vitamin D that can be obtained through sunlight exposure…"(9) However, this point is conveniently ignored. The time of exposure cited in this second reference for maximum production of previtamin D in the skin is 20 minutes for very light skin or 3 to 6 times longer (1 to 2 hours) for darkly pigmented skin, a difference that has not been shown to be a limiting factor, or an adequate explanation for rickets in dark skinned populations.

The skin pigmentation explanation is introduced again in the paper which has apparently precipitated the new AAP recommendation.(4) This paper reports a cluster of 30 breastfed African-American children in North Carolina seen with rickets between 1990 and 1999. While there may be an association between dark skin and rickets, as in other reported clusters,(10,11) cause and effect has not necessarily been shown. There are other variables which these papers do not consider. We generally do not know the nutritional status of the mothers, the calcium intake of either the children or their mothers, their socio-economic status, or their environmental circumstances in terms of pollution or sunlight exposure. It is well to remember that in the 19th century rickets was called the "English disease" and was rampant among children, famously not dark skinned, dwelling in polluted Dickensian urban environments.   Tellingly, a letter to the editor in response to the North Carolina article reported a retrospective analysis of 9 rachitic Asian infants in Birmingham, UK which implicated maternal vitamin D deficiency as the cause. Six of these infants were formula-fed and one breastfed baby was supplemented with vitamin D.(12) Maternal vitamin D deficiency may well be a major factor, not correctable by prophylactic doses of vitamin D given to their infants.

One may conclude that the AAP recommendation has not considered all the variables, and that there may be other issues beyond dark skin and breastfeeding. It evokes the idea of "racialization" recently expressed in several journals.(13,14,15) One should be careful not to use race or ethnicity as explanatory variables when other measures of socio-economic status-income, education, employment status, nutritional status, etc. more directly describe a study population. Happily, the AAP recommendation includes the statement that further research is necessary to understand why certain breastfed babies develop rickets. We heartily second that opinion.

Notwithstanding all of the above, it remains true that breastfed babies may be at risk for rickets. Maternal milk contains 15 to 50 IU/L vitamin D, which is inadequate for prophylaxis without additional sunlight exposure, and It is difficult to quantify and recommend sunlight exposure for a given infant. However, in spite of current concerns and recommendations for sun protection, rickets seems a tiny risk in New Mexico. To our knowledge only one child has been identified with nutritional rickets in the state and that was a child whose parents took the recommendation to avoid sun exposure to an extreme.(16) The child literally, never in his life, had been outside. We have an active WIC program which ensures well nourished mothers, and the Zia sun symbol remains an accurate representation of our climate.

Additionally, there is no appropriate oral prophylactic vitamin D preparation available and WIC has no funds to provide vitamin supplements. A, D and C combinations, available since the 30s for supplementing infants on now obsolete evaporated milk formulas, give the additional inappropriate message of multiple vitamin deficiencies in breastmilk.

The thrust of the Academy guideline …"does not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate."(1) In that context we feel that the risk of nutritional rickets here in New Mexico is negligible, that vitamin D supplementation will not necessarily solve the problem of nutritional rickets, and supplementation is not vital. However, those practitioners who continue to feel obligated to supplement breastfed babies should consider not starting a Vitamin D supplement until the 2 month well child visit, which is consistent with the Academy recommendation to start "within the first 2 months of life." Such delay avoids conveying a negative message during the early vulnerable period of breastfeeding.

Finally, recall that vitamin D is actually a steroid hormone and was mischaracterized early in the 20th century. The real "vitamin" is sunlight and it is not yet available in formula either.

1.Gartner LM, Greer FR et al. Clinical Report: Prevention of rickets and vitamin D deficiency: New guidelines for vitamin D intake. Pediatrics. 2003;111:908-910
2.Perez-Escamilla R, Pollitt E, Lonnerdal B, Dewey KG. Infant feeding policies in maternity wards and their effect on breast-feeding success: An analytical overview. Am J Public Health 1994;84:89-97
3.Donnelly A, Snowden HM, Renfrew MJ, Woolridge MW. Commercial hospital discharge packs for breastfeeding women. Cochrane Database Syst Rev. 2000;2:CD002075
4.Kreiter SR, Schwartz RP, Kirkman HN, et al. Nutritional rickets in African American breast-fed infants. J Pediatr. 2000;137:153-157
5.Thacher TD, Fischer PR, Pettifor JM, et al. A comparison of calcium, vitamin D, or both for nutritional rickets in Nigerian children. NEJM. 1999;341:563-568
6.DeLucia M, Mitnick M, Carpenter T. Nutritional rickets with normal circulating
      25 hydroxyvitamin D: A call for reexamining the role of dietary calcium intake in North
       American infants. JCEM. 2003;88:3539-3545
7.Barness LA. Rickets of vitamin D deficiency. Behrman RE, Kliegman RM, Arvin AM, eds. Nelson Textbook of Pediatrics. 16 ed. Philadelphia: WB Saunders; 2000:184-167
8.Fuller KE, Casparian JN. Vitamin D: Balancing cutaneous and systemic considerations. South Med J. 2001;94:58-64
9.Vieth R. Vitamin D supplementation 25-hydroxyvitamin D concentration and safety. Am J Clin Nutr. 1999;69:842-856
10.Shah M, Salhab B, Paterson D, Seikaly MG. Nutritional rickets still afflict children in north Texas. Tex Med. 2000;96:64-68
11.Pugliese MF, Blumberg DL, Hludzinski J Kay S. Nutritional rickets in suburbia. J Am Coll Nutr. 1998;17:637-641
12.Rani Pal B, Shaw NJ. Rickets resurgence in the United Kingdom: Improving antenatal management in Asians. J Pediatr. 2000;139:337-8
13.Rivera FP, Finberg L. Use of the terms race and ethnicity. Arch Pediatr Adolesc Med.2001;155:119
14.Schwartz RS. Racial profiling in medical research. NEJM, 2001;344:1392-1393
15.Goodman AH. Why genes don't count (for racial differences in health). Am J Public Health. 2000;90:1699-1702
16.Personal communication. Sue Scott, MD, Department of Pediatrics, Division of Endocrinology, UNM School of Medicine