There's a lot about Jefferson Quishpe that isn't unusual for a 13-year-old boy. He loves Dragon Ball video games. He despises vegetables. He wears his hair short and spiky. But the similarities fade on stifling hot days, when Jefferson refuses to put on a pair of shorts.
"Everybody can see my legs and I don't want them to,'' he says, staring down at his Nike P-Rod sneakers.
Crooked legs like Jefferson's haven't been seen much since the 19th Century, when rickets -- the childhood disease that softened Jefferson's bones -- crippled kids working in factories. Rickets is caused by extreme vitamin D deficiency; vitamin D, necessary for the body to absorb calcium, comes primarily from the sun.
Rickets was all but wiped out in the 1930s with the advent of fortified
PREVENTING D-DEFICIENCYNew moms: All pregnant and breast-feeding moms should take a vitamin D supplement of at least 400 international units daily.
Infants: All breast-fed babies should be given a daily dropper full of vitamin D supplement or an infant multivitamin with 400 units of D as soon as possible after birth.
Toddlers: Encourage children to drink four cups of milk a day. Give them a daily vitamin D supplement of 400 units if they don't drink a lot of milk.
All children: "It only takes 10 minutes of exposure to sunshine to activate vitamin D. Don't put on sunscreen protection until after you've been out for a few minutes. Most dermatologists are against that recommendation, so you'll have to balance that,'' said Dr. Ana Paredes of Miami Children's Hospital.
milk and kids spending more time outside. In the last 10 years, however, a stream of reports has announced the return of rickets. Although small in number, these cases foreshadow a larger problem of vitamin D-deficient children.
The fear? Today's generation will be more vulnerable to bone-cracking osteoporosis and other serious conditions recently linked to vitamin D deficiency, from diabetes to cancer to multiple sclerosis.
"This potentially is a time bomb,'' says Dr. Laura Tosi, bone chief at the Children's National Medical Center in Washington. "What I worry about is that an affluent country like ours is growing a population that is going to be old before its time.''
Medical experts can't pinpoint how widespread rickets has become because there is no national data on the disease. But after a review of Georgia hospital records in the late 1990s, the Centers for Disease Control and Prevention estimated five for every one million children under the age of 5 in this country is hospitalized with rickets. The actual numbers are believed to be higher because only 20 percent of the cases wind up in hospitals, says Kelley Scanlon, a CDC epidemiologist.
Those most vulnerable: dark-skinned, breast-fed infants. Dark skin has more difficulty absorbing vitamin D from the sun and human breast milk doesn't contain enough D.
It's the children whose vitamin D levels are low -- but not low enough to develop the obvious signs of rickets -- that doctors worry about most.
"Almost every single day, I see a kid with low vitamin D levels,'' said Dr. Ana Paredes, director of clinical research at Miami Children's Hospital. She recently screened children with chronic diseases like asthma and diabetes and found 25 percent had low bone mineral density.
"It's become extremely prevalent, even in the Sunshine State,'' she said. "We've gone from being cautious about sun exposure to now nobody gets sunlight or, when we do, we use extreme protection. The other factor is kids are getting weaned off milk very early in life.''
Childhood is a critical time for bone health, as the majority of peak bone mass develops during adolescence.
"Osteoporosis is not a disease of adulthood; it's a disease of childhood,'' says Dr. James Dowd, a Michigan rheumatologist and author of The Vitamin D Cure (Wiley, $24.95). "Think of it as a retirement savings account. You save all your bone for retirement before your 20th birthday. If you didn't save enough, you're going to run out.''
A blood test can determine vitamin D levels, but it's not something most pediatricians check.
Jefferson's mother, Monica Chuga, says she knew something was wrong when her son was still struggling to walk at age 5. Born in Ecuador, Jefferson came to the United States when he was 6 after a group of American volunteers sponsored him to go to Tampa's Shriners Hospital.
Rickets usually becomes apparent in a child's first two years of life. Infants may have seizures and high fevers; babies are slow to sit, crawl and walk. If not caught, the disease can deform a child's spine and legs, preventing him from reaching his full height and peak bone mass.
Jefferson's rickets was caused by malnutrition and chronic kidney disease. Today, under the care of pediatricians at the University of Miami/Jackson Memorial Medical Center, Jefferson can jump, run and swim with his classmates at a charter middle school in Miami. He likes to spend Friday nights boxing with his stepfather, Luis Muniz, at a Wynwood gym.
Jefferson is three feet nine inches tall -- the average height for a boy who is 6, not 13. He is expected to grow if he continues to control his condition, says Dr. Gaston Zilleruelo, chief of pediatric nephrology at UM. So Jefferson dutifully swallows Calcitriol, an active form of vitamin D, along with 12 other supplements.
Only a few foods, like oily fish, shiitake mushrooms and egg yolks, naturally contain vitamin D. Even with fortified milk, it would take at least four cups a day for children to reach the levels of vitamin D that scientists now believe their bodies need.
Thus, the sun is the single biggest source. But skin pigment, how much of the body is exposed and during what time of day affect one's sunshine quota. Many experts say lighter-skin people should get 10 to 20 minutes of sun three times a week -- and at least twice that for those with darker complexions.
"At the risk of being politically incorrect, I have to ask a parent, 'Is your kid getting enough sunlight?'‚'' says Tosi, the bone doctor in Washington. "What I generally tell my moms is that as long as children are getting good outside play time, they only need to take vitamin D supplements during the school months. The question that has no agreed-upon answer is 'how much?'.''
This fall, the American Academy of Pediatrics will raise its vitamin D recommendation for newborns to 400 units, says Dr. Frank Greer, chairman of the academy's committee on nutrition. The recommendation is double what the academy started advising five years ago, when rickets first caught the group's attention.
Vitamin D supplements should begin at birth, the academy will recommend, and continue until babies begin daily feedings of at least 17 ounces of milk fortified with vitamin D. Because infant formulas are required to be fortified with D, the recommendation doesn't apply to babies on formula.
Despite the academy's initial recommendation, only half of pediatricians follow the advice, according to an academy survey.
"The first recommendation came out when I was on maternity leave and I was waiting for my pediatrician to say, 'You know, your child needs vitamin D,'‚'' Scanlon says. "I ended up telling her about it.''
As for older children, Zilleruelo, one of Jefferson's doctors, hopes attention to vitamin D will eventually lead to more fortified foods.
"Cod liver oil was a good source for our grandparents, but try to find a child nowadays that will take that,'' says Zilleruelo. "Most schoolchildren don't even like to drink milk.''