Friday, August 29, 2008

Truth or Dare: Vitamin D and breastfeeding

The current recommendation from the AAP on breastfeeding and vitamin D is that "all infants, including those who are exclusively breastfed, have a minimum intake of 200 IU of vitamin D per day beginning during the first two months of life." When an organization like the AAP makes such recommendations/policies there are winners and losers. Who are the winners and do we really want to know the losers? Winners, of course, should be our babies, our children; since this impacts their health. Are they the winners? Does supplementation of vitamin D in the exclusively breastfed infant helpful or hurtful? Is it needed? Is it needed for all or selectively? Frankly, its hard to get a good picture on this because like anything decided in the US, economic motivation is of prime consideration. The economic winners in this policy are companies that make vitamins but also the infant formula industry. (Mead Johnson/Abbott also make vitamin drops for infants)
In 2000, a study was published in the Journal of Pediatrics by researcher Shelley R. Kreiter called, "Nutritional rickets in African American breast fed infants." It made alot of headlines around the country. I remember reading the study because I had been a WIC Breastfeeding Peer Counselor Coordinator in a Florida county from 1994-1998. Breastfeeding rates for African American women in my area were very, very low. Those who did breastfeed, most often were also using infant formula. Most did not breastfeed for long. So I was very interested in how this study defined breastfeeding. The definition of breastfeeding in research is crucial in making decisions of causation. How can researchers know that breastfeeding is the cause of the rise in rickets, if the mothers were also using infant formula, water supplementation, or foods or other drinks? In this particular study, if memory serves me there was no definition of breastfeeding. So we, the readers, do not know if breastmilk was the only source of nutrition for these infants. I would suspect NOT, because initiation rates in North Carolina for African American infants in the WIC Program ranged from 18% - 30% from the years 1993-1999. Duration rates at 6 months for the WIC Program during those years hovered at around 10%. With such low duration rates, I would believe that there was alot of supplementation going on (supplementation of formula/foods cause milk supplies to drop and is often instrumental in mother's weaning because of low supply of breastmilk). If there is no definition of breastfeeding in research, then how can we believe that the rickets were caused by African American women breastfeeding their babies? We might suspect this is a cause but until we have determined that the only food or drink these babies got was breastmilk, then how can we logically, scientifically say that their is a deficiency in breastmilk? The definition of breastfeeding is critical to the understanding of causation and in this study like the studies on hiv, the researchers saw no reason to define breastfeeding. Even WIC does not define breastfeeding in its data. Breastfeeding initiation is "ever" breastfed. Ever breastfed is dependent on the accuracy of the mother's memory and the accuracy of the WIC clerk. One might assume that breastfeeding mothers who get the "full" breastfeeding packet are exclusively breastfeeding but I learned quite quickly that often clients on the WIC full breastfeeding packets would also have infant formula (either gifted to them from the hospital/doc's office, friends/family, or bought out of pocket). So reading WIC stats does not give people outside the system a real understanding of what is going on regarding infant feeding and particularly if they aren't aware of differences in breastfeeding practices, the need for definitions. One of the authors of this study, Dr. Robert P. Schwartz (funded in other studies by Mead Johnson, Genentech) is interviewed about this study and he tells the story of how he obtained the WIC statistics--a WIC Representative gave him the breastfeeding data for part of the study (not the cases themselves but the data regarding the rise of breastfeeding rates in the North Carolina WIC population). I am somewhat amazed that WIC gave away their data. I think that is somewhat unusal.
The editorial in the Journal of Pediatrics 2000 in that particular issue of the Kreiter et al study was "Vitamin D-deficient rickets: The reemergence of a once-conquered disease." At one point it states, "The reappearance of rickets may be an unintended consequence of an admirable health initiative the promotion of human milk feeding." I find the sentence rather jarring, admirable? human milk feeding? Interesting spin....There were 3 authors to this editorial and one, Reginald C. Tsang was the author of a book called, "Vitamin & Mineral Requirements in preterm infants published by Mead Johnson.
In 2001, the CDC convened a Vitamin D Expert Panel meeting to determine the CDCs final report on vitamin D supplementation of breastfeeding infants. Some of the experts/researchers have industry funding or patents that would suggest to me that vested interests may have had a part in the conclusions that were drawn. Michael F. Holick was listed as a professor at Boston University School of Medicine. No mention of his inventions to patents on vitamin D compounds or test kits to determine vitamin D levels. (patents 4661,294, 6455714, 6291693) His test kits are based on ELISA antibody tests (remember antibody tests???? false positives). Another expert was Bruce W. Hollis, who just also happens to have a patent on a test kit for vitamin D (patent # 5821020). He was listed at this CDC panel meeting as a professor of Pediatrics at the Medical School of the University of South Carolina. Frank R. Greer, CDC expert panel member, has represented the National Dairy Association's 3-A-Day for stronger bones program. He is also the secretary/treasurer to the ISRHML (International Society of Researchers of Human Milk and Lactation). He was listed as a professor of pediatrics at Meriter Hospital, Wisconsin. Bonny L. Specker, another expert, has been funded in her research by Carnation/Nestle, on Mead Jonson Advisory Board 2004, National Dairy Council. Nancy F. Krebs has had her research funded by Mead Johnson. Of note is some very thoughtful statements made by Ruth Lawrence regarding the situation of vitamin D use for exclusively breastfed infants. (how will the gut of the exclusively breastfed infants respond) But the decision was made to supplement all breastfeeding infants.
I thought it of interest that a patent published in 1981 by Abbott Labbs (patent #4308264) on vitamin D(calcitriol 1.alpha.,25-dihydroxycholecalciferol) makes some interesting statments.
"Approximately one-third of premature infants, one-third of infants with birth asphyxia and one-half infants of insulin-dependent diabetic mothers have neonatal hypocalcemia."
"Late neonatal hypocalcemia usually occurs in full term of premature infants who have been started on feedings and show signs or symptoms of hypocalcemia only after several days or weeks of feedings."
An infant formula company describes low calcium problems and patents a vitamin D to solve the problem. But they don't blame the infant formula, calcium problems are the result of birth asphyxia, prematurity, and mostly diabetic mothers. Funny, how this all gets turned around 30 years later and the reasoning becomes that breastfeeding is one of the causes of rickets in African American infants.
Copyright 2008 Valerie W. McClain


  1. The other part of the story is that most people in the US are vitamin D deficient; we have become a nation of cave dwellers, going from homes to cars to office buildings with no time spent in the sun. We use dryers instead of hanging laundry outside, and use our cars to drive distances that are easily walkable.

    Definitions of breastfeeding are critical in research. Your point is well-taken. And the profit motives in medical research are occult and dangerous, as they are deemed more valuable than health.

    Vitamin D comes from sun exposure. If one lives above 42 degrees North or South latitude from the equator, it takes work to get enough Vitamin D for at least half the year, when the sun has moved away from one's location.

    I prefer another research based recommendation; supplement the mother with enough Vitamin D in pregnancy and lactation that her milk is sufficient. Women will more easily remember to take their own supplement than to give a daily one to their babies.

    Personally, I have found it difficult to get enough Vitamin D: I walk outside every day and take a supplement. My level was only 28 after all that...when the range is 40-60.

    Cod liver oil used to be the dread of children. My dad remembers that. Sun baths to naked babies were recommended in the 50s....these two old-time remedies need to be restored.

  2. Nikki,
    The WHO recommendation, "But 5 to 15 minutes of casual sun exposure of hands, face, and arms two to three times a week during the summer months to keep your vitamin D level high. Closer to the equator where UV levels are higher even shorter periods of exposure suffice."
    under "Myth 5-It takes a great deal of sun exposure to avoid vitamin D deficiency."

    I question the reliability of vitamin D testing. In an article in the NY Times (Jan 8, 2009) "Quest Acknowledges Errors in Vitamin D Tests," by Andrew Pollack.

    Quest Diagnostics acknowledged that thousands of people who had vitamin D levels tested in the last two years had possible erroneous results. The article states there is no standardization of tests, results can differ considerably from one lab to another. "Yet many experts say that even if the tests were accurate, there would still be uncertainty in how to treat patients."
    Despite the errors the article states, "that the company's stock price rose 80 cents to $49.20"
    I was born in Timmins, Ontario, Canada. I remember cod liver oil. Not much got down my throat because I ran faster than my mother and hid under beds. But from infancy, my mother always had me outside, even in the coldest winter weather. I think my love of the outdoors stems from being outdoors every day in my childhood.
    I don't dismiss sunlight deficiency in our world. What I dismiss is this massive attempt to test everyone and presume that we know the correct levels of this vitamin.