A vitamin to reduce respiratory illnesses? Yes!
When you think about vitamin D, do you think about rickets and assume that vitamin D must not really be an issue for your child, because who’s ever heard of anyone being diagnosed with rickets lately?? Well, rickets actually remains a modern reality, but over the past few years, there have been more and more studies showing that vitamin D is important for many things beyond bone health. Let’s take a close look at this vitamin and the recommendations surrounding it.
Vitamin D can come from two sources for us: diet, and exposure to UV-B rays in sunlight. Dietary sources for vitamin D include fatty fish (salmon, mackerel, sardines, anchovies, trout, herring, carp, and orange roughy), infant formulas, and fortified milks, with small amounts of vitamin D also found in fortified cereals, egg yolks, beef liver, cheese, and some mushrooms. Breastmilk contains minimal vitamin D, so infants who are exclusively breastfed are at a particularly high risk for vitamin D deficiency.
Vitamin D plays multiple roles within our bodies, some of which have only recently been discovered and remain under investigation. We know that vitamin D is necessary for absorption of calcium and phosphorus from the gastrointestinal tract, and thus contributes to growth and maintenance of strong bones. Rickets is a disease that presents as softened bones and skeletal deformities, and one study actually showed that one-third of infants and toddlers with vitamin D deficiency had some evidence of bone demineralization on examination of x-rays.
Other suspected benefits of vitamin D include prevention of cancer, autoimmune diseases, juvenile diabetes, cardiovascular disease, high blood pressure, and — yes– respiratory infections and childhood wheezing! Infants who have low vitamin D levels are much more likely to be diagnosed with RSV infection, and children who have vitamin D deficiency have significantly more respiratory illness and bronchitis. A recent study also showed that children who are deficient in vitamin D are more likely to be admitted to the intensive care unit in general and are likely to be sicker upon admission to the ICU than those who have higher vitamin D levels. Vitamin D appears to play a role in boosting our immune systems and giving us better overall health.
The current recommendation for vitamin D intake in infants and children is 400 IU per day, with the American Academy of Pediatrics recommending that all infants, children, and adolescents be given supplements containing this, unless they are drinking at least 32oz/day of infant formula or vitamin D-fortified milk. Few children and adolescents meet this recommendation for milk intake.
For breastfeeding infants, vitamin D supplementation should be started in the first few days of life, and it is given via an over-the-counter vitamin drop. (Do bear in mind that breastmilk is still significantly superior to formula for infant and long-term health, so don’t allow this need for vitamin D supplementation to deter you from breastfeeding! Exclusive breastfeeding is recommended for the first 6mo, with continuation of breastfeeding until at least 1yr of age and preferably longer. The WHO recommends breastfeeding for at least 2yrs.)
For toddlers, the vitamin D drop is continued until approximately age 3, at which time the child can be transitioned to a chewable over-the-counter vitamin. Vitamin D can be found in chewable multivitamins or in chewable vitamins containing only vitamin D, whichever you prefer. As children get older, they can transition to swallowable vitamins. Look for vitamin D3, rather vitamin D2, as D3 is better-absorbed. Also, keep in mind that vitamin D is best absorbed when given with foods containing some fat or oil.
In regard to dietary sources for vitamin D, the best source by far is fatty fish – salmon, in particular. One 3.5oz serving of salmon provides 360 IU, approximately 90% of the recommended daily intake. Fortified milk contains 100 IU per 8oz, so 32oz/day is required to meet the recommendation.
Sunlight exposure is another source of vitamin D, but it is not a recommended source. UV rays are associated with skin cancer, including melanoma, and the earlier infants/children are exposed to UV, the higher the risk of skin cancer later in life. Diligent use of sun protective measures, including sunscreen, is strongly recommended. Sunscreen use does block vitamin D.
As research continues, it is possible that the recommendation for vitamin D intake may increase, and hopefully, there will be more data for what exactly constitutes the healthiest range for vitamin D in the body. For now, 400 IU of supplementation, plus general dietary intake, is considered adequate. Concern for toxicity would arise with children receiving more than 2000 IU per day of vitamin D from diet and supplementation.
So take your vitamin D, everyone, and here’s to a healthier school year!
Michelle Bennett, MD