Dietary Guidelines for Calcium and Vitamin D: A New Era

Ensuring adequate intake of calcium and vitamin D are important nutritional goals for children. They are primarily important for bone growth and development, and recent data suggest the possibility of other important health benefits for these key nutrients throughout life. These new data prompted the Institute of Medicine (IOM) to reevaluate existing dietary recommendations for calcium and vitamin D. On November 30, 2010, the IOM issued a new report that provides dietary recommended intake (DRI) values for calcium and vitamin D for adults and children.1 The final publication of the report will be in 2011; thus, it will be known as the 2011 IOM report. Key pediatric values are shown in Table 1. I was a member of both the previous (1997) and current IOM committees.The previous DRI values provided only adequate intake (AI) values and, in some cases, a tolerable upper intake level (UL) for these key nutrients.2 AI is a single value that would be likely to meet the needs of most children. It is used for infants when either the content of a nutrient in breast milk is the nutritional standard or when limited data are available regarding the average requirements of a population for the nutrient (estimated average requirement [EAR]). Some knowledge or estimate of the variance around the EAR is needed to calculate the recommended dietary allowance (RDA). The better-known RDA is the intake that meets the requirements of nearly all (98%) of the population. Although both values are important in public policy, providers of pediatric care generally advise individual intakes to achieve the RDA to ensure that a child is very likely to meet his or her nutritional needs.In the 2011 report released by the IOM committee, the pediatric RDA values for calcium are similar to the previous AI values (maximum of 1300 mg/day for children aged 9–18 years). New strategies are needed, because many adolescents, especially girls, do not currently achieve this intake with diet or supplementation. Public-policy efforts focused on enhancing calcium intake by children and especially adolescents should continue on the basis of these new recommendations.For vitamin D, the previous AI was 200 IU/day for all infants and children.2 The authors of 2 recent statements (a joint report from the American Academy of Pediatrics Committee on Nutrition and Section on Breastfeeding3 and a separate statement from the Pediatric Endocrine Society [PES]4) recommended a vitamin D intake of 400 IU/day for all children; in addition, the PES statement indicated a usual target for serum 25-hydroxyvitamin D (25[OH]) of ≥50 nmol/L (20 ng/mL).4Although the 2011 IOM values and recommendations are similar to these other recommended values, there are several important differences. An AI of 400 IU/day for infants up to 1 year of age was chosen as a single intake to meet the needs of most infants. However, because more data were available for older children, an EAR of 400 IU/day and an RDA of 600 IU/day were set for children older than 1 year. Thus, 600 IU/day represents an intake of vitamin D that would meet the needs of nearly all children (98%) older than 1 year. The UL was set at 1000 IU/day for infants in the first 6 months of life but increased proportionally for older children to a maximum of 4000 IU/day in children aged 9 years and older. This UL is not a recommended dose but, rather, an upper safe intake level and should not be routinely recommended for children.After reviewing a large body of literature, the IOM did not find convincing evidence for the use of non–bone-related outcomes in establishing the EAR or RDA in any age group. Additional studies are needed related to these outcomes, but pediatricians should be aware that there have been few controlled trials, especially in children, related to vitamin D and non–bone-related outcomes.What does this mean? The new vitamin D RDA for children older than 1 year is the highest RDA ever recommended for healthy children by the IOM. It is above the amount provided by a liter (or quart) of milk or fortified juice at current fortification levels and well above typical dietary intakes for any group of children. Achieving this intake from dietary sources would require an increased proportion of fortified foods and beverages in the US food and beverage supply. For example, yogurts are increasingly but not uniformly being fortified with vitamin D. A modest increase in the concentration of vitamin D in fortified milk and juices would likely be reasonable to consider but would require statutory changes and careful consideration of the risks of such changes. Pending such changes in fortification and diet, the use of supplements will need to be considered for many children while encouraging diets with adequate calcium and vitamin D. Monitoring of the food supply related to fortification should be performed to ensure that overfortification does not occur.The 2011 IOM committee,1 in agreement with the Pediatric Endocrine Society,4 targeted a serum value for 25(OH)D of at least 50 nmol/L as meeting the needs of nearly all children (and adults).3 This value is lower than that recommended by some experts. In contrast, clinical laboratories typically report serum 25(OH)D values at <75 to 80 nmol/L as “insufficient,” even for children. However, pediatric data do not support this description. It should be noted that pediatric DRI values are not intended for populations other than healthy children. Caution should be used when providing high doses of vitamin D for children with chronic illnesses or populations such as preterm infants or routinely targeting higher 25(OH)D values.Pediatricians and families alike have been slow to accept the need for supplementation of breastfed infants with vitamin D. The 2011 IOM report provides strong support for ensuring that infants receive an average of 400 IU/day of vitamin D from dietary sources or supplements. The IOM report, as well as the American Academy of Pediatrics guidelines, does not recommend reliance on sunlight exposure to produce vitamin D in the skin in any population. Advising families that they do not need to give their children dietary or supplemental vitamin D, because there is abundant sunshine, is inappropriate advice and should be abandoned even in southern climates. Educational efforts are urgently needed in this regard because of limited compliance with current recommendations.5In summary, pending further research, providing infants younger than 1 year with a total intake of 400 IU/day and older children with 600 IU/day is advised by the 2011 IOM report to meet the needs of nearly all children. These values are slightly, but not greatly, different from current American Academy of Pediatrics guidelines. It is likely that the American Academy of Pediatrics will evaluate these new IOM recommendations and consider revising its recommendations on the basis of that review. Parents and pediatricians should be aware of the updated insights regarding slightly more vitamin D being potentially needed to meet the needs of nearly all children.Pediatric advisory panels should carefully consider the pros and cons of recommending higher vitamin D intakes, especially those above the UL, for both healthy children and those with chronic illnesses. Evidence should be derived from randomized clinical trials that include enough subjects and adequate duration of exposure to evaluate both safety and efficacy.