Some Infants and Toddlers Have Vitamin
D Deficiency
At least 40 percent of American infants and
toddlers are not getting enough vitamin D, according to a report
in Archives of Pediatrics and Adolescent
Medicine.
Twelve percent of the youngest children in
the US are already deficient in vitamin D, and another 28
percent are at risk for vitamin D deficiency, according to the
study.
Because human breast milk lacks sufficient
vitamin D, the number of babies in the research sample being
breast-fed were important to the findings.
"These data underscore the fact that
breast-fed infants should be supplemented with vitamin D," says
study author Dr. Catherine Gordon at Children's Hospital in
Boston.
She adds that mothers who are breastfeeding
often need vitamin D supplements as well.
Breastfeeding is a known risk factor for
low vitamin D levels in infants, which is why many pediatricians
routinely recommend vitamin D supplementation for breast-fed
infants.
Other factors that may contribute to low
levels of vitamin D include not drinking enough vitamin
D-fortified milk (for toddlers), staying out of the sun, or
using sunscreen.
Vitamin D, also known as the sunshine
vitamin, is produced naturally when the body reacts to sunlight.
However, the use of sunscreen and advice to
stay out of the sun - which is important for preventing skin
cancer - may also be reducing levels of vitamin D in people.
Few foods naturally contain vitamin D,
which is essential for strong bones because it helps the body
absorb calcium.
In addition to helping maintain bone
health, Dr. Gordon says that vitamin D also appears to play a
role in maintaining the immune system.
Persons with low levels of vitamin D may be
more susceptible to autoimmune diseases, such as type 1 diabetes
and multiple sclerosis, and to certain cancers.
Previously, Dr. Gordon studied vitamin D
levels in adolescents and found very high levels - about 42
percent - of vitamin D deficiency in teens. That finding made
her interested in assessing levels in younger children.
The current study included 380 children
between eight and 24 months old. About 80 percent were from
urban areas, and the majority of the youngsters were African
American or Hispanic, according to the study. However, the study
made no association between skin pigmentation and vitamin D
levels.
For this study, the researchers defined
severe vitamin D deficiency as blood levels of less than 8
nanograms per milliliter (ng/mL), vitamin D deficiency as less
than 20 ng/mL and suboptimal as less than 30 ng/mL.
Dr. Gordon says there is some debate within
the medical community about what truly signifies vitamin D
deficiency, but that they felt current evidence supports the
levels they used, and less than 20 ng/mL is the level her
hospital uses as a cut-off point.
In an accompanying editorial, Dr. James
Taylor, at the University of Washington, says that although he
believes the study was well done, Dr. Gordon and her colleagues
used a "higher cut-off" than what has been used by other
researchers.
But, he adds, because Dr. Gordon's team
found X-ray evidence of low bone density in children who fell
into their category of low levels of vitamin D, "it might be
that this might be an indication of long-term problems.
“If this is the case, then [Dr.] Gordon and
colleagues might have picked the right definition,” says Dr.
Taylor. “However, it might be that for many of the children with
osteopenia [low bone density], the changes are transient and not
indicative of disease. Time and more research will tell."
The key findings from the study say that
breastfeeding without vitamin D supplementation is a risk factor
for vitamin D deficiency, and that a higher body- mass index was
associated with a risk of vitamin D deficiency.
There was no association between the
seasons - an indication of possible sun exposure - and vitamin D
deficiency.
There was no association between skin
pigmentation and vitamin D deficiency. Consumption of vitamin
D-fortified milk confers protection against deficiency.
Dr. Gordon says it is very difficult to
consume too much vitamin D, so she recommends vitamin D
supplements for breastfeeding infants and lactating mothers. She
also recommends a multivitamin containing vitamin D for older
children.
Dr. Taylor is not as convinced about the
need for routine supplementation, however.
"I think that more research is needed
before routine vitamin D supplementation is recommended for all
children," he says.
Always consult your physician for more
information.