Research Into Practice
How Do We Help Mothers with Vitamin D Questions?
Melissa Clark Vickers, MEd, IBCLC
Huntingdon, TN, USA
From: Leaven, Vol. 45 No. 1, 2009, p. 7
Human milk deficient? Most LLL Leaders bristle at a statement like this -- we know that human milk is perfectly designed for human infants, and it is inconceivable that such a perfect substance could possibly be lacking in anything. Often, when we hear about a human milk deficiency, a closer look reveals some kind of bias that starts with using something other than human milk as the standard. So why is vitamin D any different?
As Dr. Will, Dr. Taylor, and Dr. Wagner note in the lead article, the potential for vitamin D deficiency in human milk is not through some error of nature. Instead, we have to look at the broader picture. Human milk is perfectly designed for humans, who are physiologically capable of getting the needed vitamin D through the simple act of daily sun exposure. Our skin cells make the precursor for vitamin D, and a little ultraviolet B (UVB) radiation converts it to vitamin D. This natural system works without worrying about how much vitamin D might be in a mother's milk to be passed along to her infant. So why the problem?
Sun exposure is a key issue in vitamin D deficiency. Whereas our ancestors spent much of their lives in the sun, today we try to avoid such exposure for fear of skin cancer. If we go out in direct sunlight, we are cautioned to cover exposed skin with clothing and sunscreen to block those UVB rays that are otherwise helpful in vitamin D formation. Even adults who ignore these warnings are likely to take them quite seriously when it comes to protecting their infants. The result of this needed protection from harmful sun damage is an inadvertent disabling of the skin's vitamin D manufacturer. It is not surprising, therefore, that vitamin D deficiency is rapidly increasing across the globe -- in adults and children.
Because we protect the infant from the sun, we have to make sure he gets the vitamin D he needs.
Can't we just supplement the mother?
As the article points out, it is possible to increase the amount of vitamin D in human milk through supplementation of the mother. So why can't we just ask her to take additional vitamin D? Vitamin D is fat-soluble vitamin, which makes toxicity an issue. Toxicity with water-soluble vitamins such as vitamin C is much less of a concern, because excess amounts are readily excreted in urine. The fat-soluble vitamins can collect and be more difficult to get rid of.
Whereas there are official recommended daily amounts of vitamin D for lactating mothers and women in general, we really don't have enough solid research yet to know how much is too much, and how much would really be needed in order to provide enough vitamin D in human milk for a growing infant's needs. Research is being conducted, and perhaps soon we'll have a better solution for our breastfeeding infants. Until then, however, we are left with the reality that the infant requires vitamin D in larger amounts than is likely to come through his mother's milk. We are also not sure of how much sun exposure is needed to provide the naturally forming vitamin D in the infant's skin. This is further complicated by such things as latitude (and related sun exposure) and color of the skin (darker skinned people are more at risk for vitamin D deficiency because of the added protection from the sun's harmful rays by that darker pigment).
We also know that there are serious consequences of a vitamin D deficiency, ranging from the commonly mentioned rickets, to more serious immunological disorders and cancer. Long-term effects of vitamin D deficiency -- or even just insufficiency -- are not well known at this time, and are not worth risking an infant's long-term health to find out.
How do we help the mother who comes to us with a vitamin D question?
It is important that Leaders share appropriate information with mothers who ask if vitamin D supplementation is really necessary. There are a number of points that can be made:
- Human milk does not appear to have adequate amounts of vitamin D for a growing infant.
- This is not an indication that human milk is somehow inferior to a commercial formula that has adequate amounts of vitamin D already in it.
- It is our change in lifestyle that has necessitated vitamin D supplementation. Lack of adequate sun exposure is the direct culprit for this change -- and the dangers of repeated sun exposure are well documented.
- The American Academy of Pediatrics now recommends that all infants and children should be supplemented with a minimum of 400 IU per day of vitamin D, beginning in the first few days of life.
- Adults also need to ensure adequate vitamin D intake. This is especially true for women who are pregnant or breastfeeding. Not only are they protecting themselves, but they are also helping to protect the growing fetus or infant.
- Vitamin D -- either by itself or as part of a multi-vitamin supplement -- is readily available and inexpensive in many areas.
- Mothers should dialogue with their health care professionals about appropriate vitamin D supplementation.
The Bottom Line
Human milk is still the standard for infant feeding. Further research may lead to new recommendations on vitamin D supplementation, but in the meantime, a mother should feel confident in continuing to breastfeed her child -- while supplementing with vitamin D.