Search This Blog

10 May 2010

Infants Need More Vitamin D

Why anyone listens to doctors when it comes to anything related to diet and environment is beyond me. They’re always getting it wrong. They were wrong on fiber and diverticular disease for decades. They were wrong on the impact of pesticides and xenoestrogens released into the environment for years, too. And of course they were wrong on trans fatty acids until just a couple of years ago. Now it looks like they’ve been wrong on exposure to sunlight and the use of vitamin supplements. Hardly surprising! Ever since we all began covering up, on their advice, to avoid getting skin cancer, vitamin D shortage has become a serious problem among both kids and adults. The problem is that there are only two ways to get vitamin D — exposure to ultraviolet light and supplementation. Without either enough sun exposure or adequate supplementation, we all face vitamin D shortage and the concomitant problems of weak bones and vulnerability to disease. And thanks to your doctor’s advice, you’re short on both.

Now, a new study has found that most infants, whether bottle or breast-fed, get far too little vitamin D. The study, conducted by the Centers for Disease Control (CDC), surveyed nine groups of mothers of children aged one to 10.5 months old. Each group contained between 1,633 and 1,952 mothers. The results showed that only five to 13% of breastfed infants (you read that correctly) and 20% to 37% of formula-fed babies get enough vitamin D daily. Back in 2008, the American Academy of Pediatrics recommended that the minimum daily requirement of vitamin D be doubled because children now get far less sun now than in the past. Well, the medical community missed on that one too. The new study reflects shortages even at those higher levels.

The news came as a surprise to many physicians and patients, who assumed that formula, at least, provided the requisite amount of vitamin D. But in order to get the required amount of vitamin D from formula, babies would need to drink a full liter (34 ounces) a day, and most don’t come close to drinking that much. Baby formula does provide a richer source of vitamin D than does breast milk (more on this later) — but, as it turns out, richer doesn’t necessarily mean rich enough, given that about 2/3 of all formula-fed babies are vitamin-D deficient (again, compared to 95 percent of breast-fed infants). And babies can’t make up the shortfall from food sources like eggs and fish. In fact, it’s virtually impossible for anyone to meet minimum requirements of vitamin D through food. Sun is the best source, but again experts recommend against exposing infants to sun without protection, given the risks.

The risks of vitamin D shortage are also considerable, particularly for infants. Historically, the possibility of rickets was the biggest concern, causing bowing of the legs bone deformities, slow growth, swelling of wrists and ankles, and possibly breathing problems. But as Dr. Carrie Drazba, M.D., a pediatrician at Rush University Medical Center, in Chicago, points out, “We’re finding out that there are other risks associated with vitamin D deficiency besides rickets. A lot of cells in our body have receptors for vitamin D.”

In fact, studies have found that vitamin D bolsters the immune system and may protect against heart disease, certain cancers, schizophrenia, autoimmune disorders, respiratory ailments, and type 1 diabetes in children. Several studies last year found that vitamin D shortages in childhood may lead to a host of heart-risk factors, including high blood pressure, high blood glucose, and low HDL (or good cholesterol), later in life.

Adding fuel to the fire of the CDC study, simultaneous research from Boston Medical Center, just published in Pediatrics, also found high levels of vitamin D deficiency, this time in newborns and their moms. In this Boston study, 433 women and 376 newborns provided blood samples obtained within 72 hours of birth. Shockingly, 58 percent of the newborns had vitamin D deficiencies, as did 36 percent of mothers, with severe deficiencies showing up in about two-thirds of those cases. (More on this later.)

The solution, the experts contend, is to supplement. “We found that most infants, not just those who are breast-fed, may require an oral vitamin D supplement daily, beginning within their first few days of life, to meet the 2008 AAP recommendation that infants consume at least 400 IU/day of vitamin D,” said study director Dr. Cria G. Perrine. (More on this later.)

Apparently, most doctors still don’t recommend supplementation to their patients. In fact, as few as one percent of formula-fed babies and five-percent of breast-fed babies actually take vitamin D supplements. Frank R. Greer, MD, who headed the committee that came up with the new guidelines for vitamin D intake, says, “I am frankly surprised that more pediatricians are not recommending supplementation, especially to new moms who are breastfeeding.” (More on this later.) The study authors believe that many doctors are unaware that the recommendations have increased. They note, “Because physicians’ knowledge of the AAP [vitamin D] recommendations has been positively associated with the likelihood of their recommending vitamin D supplements, both healthcare providers and parents need to be educated about the AAP guidelines and the importance of vitamin D nutrition, including that infants should not be exposed to sunlight and, thus, need an alternate source of vitamin D.”

In fact, the Institute of Medicine is actively considering again raising its guidelines for vitamin D intake for adults as well as for children and will announce its decision in the coming months. I’ve written before that even with the higher levels of recommended intake, the guidelines for vitamin D are conservative, at best. Currently, the guidelines call for 400 IU a day for kids, but even a few minutes of sun exposure can generate 2000-4000 or more IU. Vitamin D toxicity does not usually develop below 10,000 units per day (for adults), so there’s plenty of room to increase the recommended dose. The second study found that even among those mothers who took prenatal vitamin D supplements in the last trimester of pregnancy, 30 percent remained vitamin-D deficient at the time of birth, showing that at current recommended levels, supplementing isn’t sufficient. (More on this later.)

“The most obvious way to correct deficiency is sensible sun exposure,” said the director of the second study, Dr. Anne Merewood. “While a sunburn should be avoided, even a small amount of time spent outdoors was protective against deficiency.” Most pediatricians insist that babies should not get sun exposure — period — unless they have on sunscreen and clothing that protects them, so this advice won’t help with doctor-abiding infants though it might help their moms.

Throughout this blog, I’ve been repeatedly saying, “More on this later.” And now we come to it. There is one simple reason that ties all of these problems together, that accounts for babies being born vitamin D deficient, for breast milk being deficient, and for infants being vitamin D deficient. Thanks to the medical community’s recommendations to avoid the sun and to restrict vitamin D supplementation to dangerously low levels, mothers themselves are vitamin D deficient. If mom is deficient, any baby is going to be born deficient by definition. The fetus can’t manufacture vitamin D from thin air. Likewise, if mom is deficient, then her breast milk will be deficient. Again, vitamin D can’t appear in the milk out of thin air. And finally, if vitamin D levels are insufficient in breast milk, then where is the infant going to get their vitamin D from — particularly if their doctor has banned them from the sun and is prescribing insufficient levels of supplementation.

The solution is for parents to supplement at higher levels (up to 2000 IU daily), enjoy short stints of 10 to 15 minutes in the sun (early morning or late afternoon), and lose weight to enhance vitamin D absorption. Doing these things should minimize the likelihood of passing on a deficiency to offspring. (Note: studies show that the dose required to achieve a healthy blood level of vitamin D is somewhere in the neighborhood of 1,000–4,000 IU per day — which is still less than that obtained through several minutes of sun exposure. Vitamin D toxicity does not usually develop below 10,000 units per day.) As for the babies, a few minutes of unprotected exposure to sunlight (again, early morning or late afternoon) is still your best bet. And keep in mind that the body’s production of vitamin D is self regulating. You cannot OD on vitamin D based on sun exposure alone. But if you feel more comfortable following your pediatrician’s advice to keep your baby out of the sun, then you’ll want to give your child up to a 1,000 IU a day of a high-quality vitamin D supplement.

1 comment:

Christopher Wiechert, C.N.C. said...

Great post. Keep up the great work on educating people. From a fellow professional, HealthBlogger.

http://cwiechert.blogspot.com/2010/05/whenever-possible-think-prevention-and.html

ShareThis