Vitamin D Sufficiency for Child Development and Nutrition for All
Vitamin D and calcium are required to build strong bones and teeth. Vitamin D is essential for normal absorption of calcium. Rickets, a failure in bone mineralization, was identified in the early 17th century and became endemic in the 20th century with industrialization. People were spending more time indoors and air pollution was reducing sun exposure. With vitamin D fortification and supplementation, rickets almost completely disappeared in the 21st century. However, rickets is re-emerging as fluid milk consumption decreases and people spend more time indoors and/or reducing skin exposure to sun.
Schroth and colleagues recruited pregnant women from an economically disadvantaged urban setting. Serum 25(OH)D levels were measured. One-third were vitamin D deficient although the average serum (OH)D3 concentration (48 nmol/L) of these women would almost be considered sufficient (50 nmol/L). Dental examinations of infants were conducted at 1 year of age. Lower prenatal 25(OH)D3 concentrations were associated with higher early childhood caries and enamel hypoplasia.
This study demonstrates that maternal vitamin D status during pregnancy may influence childhood tooth (and bone? ) development.
There is a second lesson – the risk of applying the law of averages.
According to the Dietary Reference Intakes for Calcium and Vitamin D expert committee, “the vitamin D-related bone health needs of approximately one-half of the population may be expected to be met at serum 25OHD concentrations between 30 and 40 nmol/L (12 and 16 ng/mL); most of the remaining members of the population are likely to have vitamin D needs met when serum concentrations between 40 and 50 nmol/L (16 and 20 ng/mL) are achieved. Failure to achieve such serum concentrations place persons at greater risk for less than desirable bone health as manifested by, depending upon age, increased rates of bone accretion, mineral density, and fractures.” The study be Schroth and associates demonstrates that having a population average which is sufficient (50 nmol/L) fails to protect many children (and their mothers).
My critics will point out that the study was conducted in an economically disadvantaged setting. It is true that this population may be more vulnerable and exhibit greater variability in vitamin D status with more people at the low end of the spectrum than observed in a nationally representative survey. After all, many factors affect vitamin D status – skin pigmentation, clothing, sunscreen use, age, obesity, latitude, season, atmospheric conditions. However, in a population of pregnant women who can be characterized as vitamin D sufficient (on average), there is little doubt that many children face unnecessary developmental risks during the first 1000 days of life.
Personalizing nutrition requires more than meeting an average score. Nutrition needs to be a right for all.
Schroth RJ, Lavelle C, Tate R, Bruce S, Billings RJ, Moffatt MEK. Prenatal vitamin D and dental caries in infants. 2014 Pediatrics doi: 10.1542/peds.2013-2215
Misra M, Pacaud D, Petryk A, Collett-Sokberg P, Kappy M. Vitamin D deficiency in children and its management: Review of current knowledge and recommendations. 2008. Pediatrics doi: 10.1542/peds.2007-1894
Stewart H, Dong D, Carlson A. Why are Americans consuming less fluid milk? A look at generational differences in intake frequency. 2013 A report summary from the Economic Research Service. May 2013
Tsiaras WG. Weinstock MA. Factors influencing vitamin D status. Acta Dermato-Veneroelog doi: 10.2340/00015555-0980