Vitamin D deficiency Rickets in breast-fed Infants
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Vitamin D deficiency Rickets in breast-fed Infants:

1) Vitamin D deficiency in pregnant and breast-feeding women and their infants.
Daaboul J, Sanderson S, Kristensen K, Kitson H, Northwestern University Medical School, Division of Endocrinology, Children's Memorial Hospital, Chicago, IL, J Perinatol. 1997 Jan-Feb;17(1):10-4.

We describe the cases of five consecutive infants with symptomatic vitamin D deficiency and their mothers. Four of the infants were light skinned, all had poor sunlight exposure, and all were breast-fed or had diets low in vitamin D. All mothers had vitamin D deficiency. Regardless of race, infants with poor sunlight exposure and diets lacking in vitamin D are at risk for vitamin D deficiency. Mothers of these infants should be evaluated for vitamin D deficiency. Vitamin D supplementation of the breast-feeding mother at risk and her infant is recommended.

2) Minnesota rickets. Need for a policy change to support vitamin D supplementation.
Eugster EA, Sane KS, Brown DM, Division of Pediatric Endocrinology, University of Minnesota, Minn Med. 1996 Aug;79(8):29-32.

Vitamin D deficiency rickets, once considered the most common disease of early childhood, was reported to have disappeared by the 1960s. However, during a recent 18-month period, seven cases of nutritional rickets were diagnosed in the Twin Cities metropolitan area. All of the patients were born at term and were breastfed without supplementation vitamins. Three of the patients were Caucasian, three were African American, and one was biracial. This case series demonstrates the risk of nutritional rickets in breastfed infants in our northern climate, regardless of race. In hopes of eradicating this completely preventable disease, we advocate a uniform policy of vitamin D supplementation to breastfed infants.

3) Variable presentations of rickets in children in the emergency department.
Bloom E, Klein EJ, Shushan D, Feldman KW. Department of Pediatrics, University of Washington and Children's Hospital and Regional Medical Center, Seattle, WA, Pediatr Emerg Care. 2004 Feb;20(2):126-30.

Vitamin D-deficient rickets is uncommon but becoming more prevalent in the pediatric population likely related to increases in breast-feeding. It should be considered in many clinical situations. We present 3 cases of rickets presenting acutely to the emergency department. Their presentations included a fracture concerning for child abuse, tetany, and hypocalcemic seizures. In all cases, laboratory and radiographic evaluations were consistent with the diagnosis of nutritional rickets and their symptoms were related to rickets resolved with appropriate treatment. Although uncommon, vitamin D-deficient rickets should be considered in children with the above presentations.

4) Nutritional rickets in suburbia.
Pugliese MT, Blumberg DL, Hludzinski J, Kay S, Department of Pediatrics, Nassau County Medical Center, East Meadow, New York, J Am Coll Nutr. 1998 Dec;17(6):637-41.

OBJECTIVE: Vitamin D deficiency continues to be a problem in pediatrics. This report presents four children, one Caucasian male and three African-American females aged 4 to 24 months who were treated for vitamin D deficiency rickets. METHODS: One female was diagnosed in the Emergency Department during evaluation of a viral syndrome, another presented with hypocalcemic seizures and the third was a self-referral for evaluation of widened wrists. The male had biochemical rickets discovered incidentally during a hospitalization for pneumonia. All were breastfed without formula supplements. Two families practiced Islam and the mothers wore veils. The females had a weight deficit for height. The females demonstrated a rachitic rosary, widening of the wrists and leg bowing. At diagnosis the serum calcium was 5.0-8.6 mg/dl, the inorganic phosphorus was 1.5-3.9 mg/dl and the alkaline phosphatase was 408-3324 U/L. The serum intact parathormone levels and the vitamin D levels were measured at Nichols Laboratories. The 25-OH vitamin D levels were 2-22 ng/ml and the 1,25(OH)2 vitamin D levels were 14-122 pg/ml. All had elevated parathormone levels. The three females had roentgenographic evidence of rickets. Two of the children also demonstrated iron deficiency. RESULTS: All patients responded to Vitamin D supplements, beginning at 2000 IU for the male and 8,000-10,000 IU daily for the females. Two children were also given calcium supplements. The three females all showed complete healing of the rickets radiologically within six months. The serum intact parathormone demonstrated an inverse correlation with the serum calcium during recovery. CONCLUSION: Vitamin D deficiency does still occur. Breastfed children of multiparous mothers, with increased skin pigmentation, living in the higher latitudes are at increased risk and would benefit from vitamin D supplementation while breastfeeding.

5) Mineral and vitamin D adequacy in infants fed human milk or formula between 6 and 12 months of age. Hillman LS, University of Missouri, Columbia School of Medicine 65212, J Pediatr. 1990 Aug;117(2 Pt 2):S134-42.

During the latter half of an infant's first year, adequate mineral and vitamin D intakes may be important not only for the prevention of rickets but also for the attainment of optimal adult peak bone mass. Ingestion of 400 IU vitamin D per day, either as a supplement or contained in formula or table milk, will result in normal serum concentrations of vitamin D,25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D. Human milk from a vitamin D-sufficient mother provides a marginal amount, less than 100 IU/L/day of total vitamin D activity from the vitamin D and 25-hydroxyvitamin D. Infants exclusively fed human milk of vitamin D-deficient mothers, who do not receive additional vitamin D or adequate exposure to sunlight, are at significant risk for vitamin D-deficiency rickets.

6) Secondary prevention of vitamin D-deficiency rickets.
Spence JT, Serwint JR, Division of General Pediatrics and Adolescent Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, jespence@jhmi.edu, Pediatrics. 2004 Jan;113(1 Pt 1):e70-2.

Reports of vitamin D-deficiency rickets continue among inadequately supplemented, dark-skinned breastfed infants. Despite the new vitamin D dietary guidelines, there remain significant numbers of unsupplemented breastfed infants. Here we report a case of subclinical vitamin D-deficiency rickets. This patient had biochemical and radiographic but not clinical evidence for rickets. We propose a new step of screening high-risk infants for subclinical rickets using wrist films paired with 25-hydroxyvitamin D levels.

7) Prevention of rickets and vitamin D deficiency: new guidelines for vitamin D intake.
Gartner LM, Greer FR; Section on Breastfeeding and Committee on Nutrition. American Academy of Pediatrics, Pediatrics. 2003 Apr;111(4 Pt 1):908-10.

Rickets in infants attributable to inadequate vitamin D intake and decreased exposure to sunlight continues to be reported in the United States. It is recommended that all infants, including those who are exclusively breastfed, have a minimum intake of 200 IU of vitamin D per day beginning during the first 2 months of life. In addition, it is recommended that an intake of 200 IU of vitamin D per day be continued throughout childhood and adolescence, because adequate sunlight exposure is not easily determined for a given individual. These new vitamin D intake guidelines for healthy infants and children are based on the recommendations of the National Academy of Sciences.

8) Nutritional rickets in African American breast-fed infants.
Kreiter SR, Schwartz RP, Kirkman HN Jr, Charlton PA, Calikoglu AS, Davenport ML. Department of Pediatrics, Brenner Children's Hospital and Health Services, Wake Forest University School of Medicine, Winston-Salem, North Carolina, J Pediatr. 2000 Aug;137(2):153-7.

OBJECTIVE: To analyze the characteristics of infants and children diagnosed with nutritional rickets at two medical centers in North Carolina in the 1990s. STUDY DESIGN: The physical and radiographic findings, calcium, phosphorus, alkaline phosphatase, and 25-hydroxyvitamin D levels of infants and children diagnosed with nutritional rickets at two medical centers were reviewed. Breast-feeding data were obtained from the North Carolina Women, Infants and Children Program (WIC). RESULTS: Thirty patients with nutritional rickets were first seen between 1990 and June of 1999. Over half of the cases occurred in 1998 and the first half of 1999. All patients were African American children who were breast fed without receiving supplemental vitamin D. CONCLUSION: Factors that may have contributed to the increase in referrals of children with nutritional rickets include more African American women breast-feeding, fewer infants receiving vitamin D supplements, and mothers and children exposed to less sunlight. We recommend that all dark-skinned breast-fed infants and children receive vitamin D supplementation.

9) Nutrition influences bone development from infancy through toddler years.
Specker B, Ethel Austin Martin Program in Human Nutrition, South Dakota State University, Brookings, SD, Bonny_Specker@sdstate.edu, J Nutr. 2004 Mar;134(3):691S-695S.

During the last decade a greater appreciation has developed for determining factors that influence bone accretion in healthy children. Nutritional factors that may contribute to bone accretion in infants and toddlers include maternal nutritional status during pregnancy, type of infant feeding, calcium and phosphorus content of infant formula, introduction of weaning foods, and diet during the toddler and preschool years. Maternal vitamin D deficiency during pregnancy is associated with disturbances in neonatal calcium homeostasis, and maternal calcium deficiency leads to reduced neonatal bone mineral content (BMC). Preterm infants are at increased risk of osteopenia, and, although the use of high mineral formula has reduced the risk of osteopenia in these infants, it has not eliminated it. The reason for the long-term bone deficiency among preterm infants is not clear, although lower physical activity levels have been suggested as a potential cause. Studies find that human milk-fed infants have lower bone accretion than do formula-fed infants; that the greater the mineral content of formula, the greater the bone accretion; and that the inclusion of palm olein oil in infant formula may reduce bone mineral accretion. Bone accretion is not influenced by the timing of the introduction of weaning foods, despite higher serum parathyroid hormone (PTH) concentrations among infants who receive solids earlier. There is evidence of calcium intake-by-gene and calcium intake-by-physical activity interactions among toddlers and young children. The long-term effects of these early nutritional influences on later bone health are unknown.

10) Do North American women need supplemental vitamin D during pregnancy or lactation?
Specker BL. Department of Pediatrics, University of Cincinnati Medical Center, OH, Am J Clin Nutr. 1994 Feb;59(2 Suppl):484S-490S; discussion 490S-491S.

Studies in European and other countries have shown that vitamin D deficiency during pregnancy may adversely affect fetal growth, bone ossification, tooth enamel formation, and neonatal calcium homeostasis. Whether effects of vitamin D deficiency on pregnant or lactating mothers differ from effects observed in nonpregnant or nonlactating women is not clear. Poor maternal vitamin D status during lactation results in low breast-milk vitamin D. However, human milk usually contains small vitamin D amounts and, under normal circumstances, the sunshine exposure of human-milk--fed infants is the major factor affecting their vitamin D status. Mothers at risk of vitamin D deficiency are those who avoid dairy products, which are routinely vitamin D fortified, and live in more northern latitudes. Dark-skinned women also are theoretically at risk of vitamin D deficiency. Sunshine exposure is a major vitamin D source, and given adequate exposure, supplemental vitamin D is not necessary. However, defining adequate sunshine exposure is difficult.

11) An outbreak of vitamin D deficiency rickets in a susceptible population.
Bachrach S, Fisher J, Parks JS, Pediatrics. 1979 Dec;64(6):871-7.

Nutritional, racial, cultural, and environmental factors have combined to produce a resurgence of vitamin D deficiency rickets in urban Philadelphia. Between January 1974 and June 1978, 24 cases were diagnosed at the Children's Hospital of Philadelphia. Patients' ages ranged from 4 to 58 months. Presenting complaints included seizures, swollen wrists, pathologic fractures, and developmental regression. Sixteen patients were below the third percentile for length and weight. Laboratory results indicated vitamin D deficiency in nursing mothers as well as in infants. All infants had been breast-fed and all were black. Ingestion of vitamin D was limited by exclusion of meat and/or dairy products in 21, and no infants had consistently taken supplemental vitamins. Nineteen were members of Muslim or Seventh Day Adventist faiths. Endogenous synthesis of vitamin D was limited by dark skin, by dressing in long garments with hoods and veils, and by air pollution in a densely populated northern city. The return to a more "natural" diet, free of food additives, has been accompanied by the return of a classic disease of industrial society. Effective management required patience and respect for religious convictions. With treatment, there was correction of chemical and skeletal abnormalities, but few patients showed catch-up growth.

12) Osteomalacia of the mother--rickets of the newborn.
Park W, Paust H, Kaufmann HJ, Offermann G, Eur J Pediatr. 1987 May;146(3):292-3.

During the last 4 years we observed four cases of neonatal rickets. The mothers of the infants suffered from osteomalacia for 1-3 years prior to its diagnosis shortly after the birth of their children. All four infants were born with craniotabes, and one infant had, in addition, a radial fracture. The diagnoses were confirmed by radiological and laboratory tests which revealed a rarefied bone structure, decreased serum 25-hydroxy-vitamin D and increased alkaline phosphatase levels in all patients. The disorder regressed under low-dose vitamin D3 therapy

13) Bone mineral content and serum 25-hydroxyvitamin D concentration in breast-fed infants with and without supplemental vitamin D.
Greer FR, Searcy JE, Levin RS, Steichen JJ, Asch PS, Tsang RC, J Pediatr. 1981 May;98(5):696-701.

Eighteen term, healthy, appropriate for gestational age, breast-fed infants were studied in a double-blind prospective study to determine whether or not supplemental vitamin D affected bone mineralization. Nine infants were randomly assigned to a vitamin D supplement of 400 IU/day and nine infants to a placebo. By 12 weeks of age, infants receiving placebo had a significant decrease in bone mineralization and in serum 25-hydroxyvitamin D concentrations compared to the vitamin D-supplemented group. Supplemental vitamin D may be necessary for optimal bone mineralization in term breast-fed infants.

14) Plasma concentrations of vitamin D metabolites in unsupplemented breast-fed infants.
Markestad T, Eur J Pediatr. 1983 Dec;141(2):77-80.

The data suggest that fetal stores of vitamin D may be rapidly depleted, and that breast milk may be inadequate as the only source of vitamin D, even for breast-fed infants of vitamin D-supplemented mothers.

15) 25-Hydroxyvitamin D levels during breast-feeding with or without maternal or infantile supplementation of vitamin D.
Ala-Houhala M, J Pediatr Gastroenterol Nutr. 1985 Apr;4(2):220-6.

Serum 25-hydroxyvitamin D (25-OHD), calcium, phosphorus, magnesium, and alkaline phosphatase levels of breast-fed infants and their mothers were studied by following 100 healthy term mother-infant pairs with different supplementation protocols of vitamin D. A pilot study in winter revealed that six of eight breast-fed infants without vitamin D supplementation had serum 25-OHD levels below the risk limit for rickets (5 ng/ml) at the age of 8 weeks. In the main study in winter groups, it was found that the 25-OHD levels were low (5.6 +/- 3.7 ng/ml) at the age of 8 weeks in the unsupplemented breast-fed infants, whose mothers were given vitamin D supplementation of 1,000 IU/day during lactation (group I), compared with the levels of those infants receiving either 400 (18.0 +/- 8.4 ng/ml, group II) or 1,000 IU (22.8 +/- 11.2 ng/ml, group III) vitamin D (group I vs. group II or III, p less than 0.001; group II vs. group III, NS). In group I 10 of 18 infants had serum 25-OHD levels less than 5 ng/ml compared with none of the infants in groups II and III. Yet the infants with 25-OHD levels less than 5 ng/ml showed no signs of clinical or biochemical rickets at the age of 8 or 20 weeks.

16) Nutritional rickets in breast-fed infants.
Cosgrove L, Dietrich A, J Fam Pract. 1985 Sep;21(3):205-9.

A ten-year literature review was prompted by the fortuitous discovery of nutritional rickets in a "well child." Sixty-three cases were identified, suggesting that this disease is not so rare as thought. Rickets should be considered in the differential diagnosis of nonspecific musculoskeletal complaints and poor growth. Vitamin D supplementation in breast-fed children should be prescribed more often.

17) Vitamin D requirements and vitamin D intoxication in infancy.
Mehls O, Wolf H, Wille L, Int J Vitam Nutr Res Suppl. 1989;30:87-94.

Without vitamin D supplementation, the majority of infants seems to be at risk of vitamin D-deficiency rickets. On the other hand, routine vitamin D supplementation of breast-fed infants is not recommended by all authors. In this paper we give an overview of vitamin D metabolism and vitamin D regulation in newborns, which may differ in a certain way from the regulation in adults. Based on this, minimal and optimal requirements for vitamin D in newborns and infants is determined. Furthermore, the paper aims at defining dosages and conditions that are at risk of vitamin D intoxication.

18) Nutritional rickets.
Feldman KW, Marcuse EK, Springer DA. Odessa Brown Children's Clinic, Children's Hospital and Medical Center, Seattle, Washington, Am Fam Physician. 1990 Nov;42(5):1311-8.

Nutritional rickets was diagnosed in 18 infants aged eight to 24 months. Clinical features included progressive leg bowing, poor linear growth, a diet deficient in vitamin D, seizures, and abnormal serum calcium, phosphate and alkaline phosphatase levels. Wrist radiographs and serum alkaline phosphatase levels were the most useful confirmatory tests. Breast milk may not contain enough vitamin D to protect infants, particularly dark-skinned children and those living in cloudy, northern U.S. cities, from rickets after six months of age. As breast feeding becomes more widely practiced, care is required to ensure that infants at high risk for rickets receive appropriate vitamin D supplementation.

19) Fat-soluble vitamin deficiency in infants and children.
Argao EA, Heubi JE, Division of Gastroenterology and Nutrition, Children's Hospital Research Foundation, University of Cincinnati College of Medicine, OH, Curr Opin Pediatr. 1993 Oct;5(5):562-6.

It is worth noting that among the pediatric population, exclusively breastfed infants, in general, are at risk for hypovitaminosis D, and at even greater risk in the absence of adequate exposure to sunlight or when the maternal diet is not sufficient to provide for vitamin D requirements.

20) Nutritional rickets still afflict children in north Texas.
Shah M, Salhab N, Patterson D, Seikaly MG, University of Texas Southwestern Medical Center at Dallas, Tex Med. 2000 Jun;96(6):64-8.

Nutritional rickets is uncommon in North America, particularly in regions where sunlight is plentiful. Recent epidemics in North America occurred in dark-skinned toddlers with poor nutrition who had insufficient exposure to sunlight and whose parents were members of ethnic, social, and socioeconomic groups with predisposing practices. Nine children (8 toddlers and 1 infant) were referred to the Bone Metabolic Clinic at Texas Scottish Rite Hospital for suspected rickets between October 1997 and October 1998. The diagnosis of nutritional rickets was based on clinical, biochemical, and radiological evidence. All children were dark-skinned: 8 were African Americans and 1 was of Hispanic parentage. All children were breast-fed with minimal intake of dairy products; none received vitamin supplementation. Radiological and biochemical rachitic changes remitted within 3 months of vitamin D therapy combined with dietary modification. Primary care providers should consider vitamin D supplementation in all infants with increased skin pigmentation and especially in those who are primarily breast-fed. Nutritional rickets can develop in dark-skinned infants of any social or ethnic background. Residing in a geographical area with abundant sunlight is not a guarantee against the development of nutritional rickets in dark-skinned children.

21) A comparison of breastfed children with nutritional rickets who present during and after the first year of life.
Peng LF, Serwint JR. Department of Pediatrics, Johns Hopkins Children's Center, Baltimore, Maryland, Clin Pediatr (Phila). 2003 Oct;42(8):711-7.

This study compares the patient characteristics of breastfed children in Baltimore, Maryland from 1990 to 2000 diagnosed with nutritional rickets at 12 months or younger to those older than 12 months to gain a better understanding of nutritional and environmental factors. All 30 of the patients were African American. Patients 12 months or younger (n=15) compared to those older than 12 months (n=15) were more likely to be born during the summer and to present with seizures and hypocalcemia. We recommend vitamin D supplementation of all breastfed infants at an early age and that supplementation continue throughout the duration of breastfeeding.

22) Sunshine exposure and serum 25-hydroxyvitamin D concentrations in exclusively breast-fed infants.
Specker BL, Valanis B, Hertzberg V, Edwards N, Tsang RC, J Pediatr. 1985 Sep;107(3):372-6.

The relationship between serum 25-hydroxyvitamin D (25-OHD) concentrations and sunshine exposure in 61 term, exclusively breast-fed infants younger than 6 months of age was investigated. Sunshine exposure was quantitated using a sunshine and clothing diary, which was verified by infant-adapted ultraviolet dosimetry. By multiple regression techniques, infant serum 25-OHD concentrations were significantly related to UV exposure and maternal serum 25-OHD concentrations. Infant 25-OHD concentrations correlated with sunshine exposure in infants whose mothers had low (less than 35 ng/ml) or high (greater than 35 ng/ml) serum concentrations of 25-OHD (r = 0.70, P less than 0.001 and r = 0.53, P = 0.004, respectively). Estimates were made to determine sunshine exposure conditions necessary to maintain serum 25-OHD concentrations above the lower limit of the normal range (11 ng/ml). A conservative estimate would be 30 minutes per week wearing only a diaper or 2 hours a week fully clothed without a hat.

23) Do breastfed infants need supplemental vitamins?
Greer FR. Departments of Pediatrics and Nutritional Sciences, University of Wisconsin, Madison, Wisconsin, frgreer@facstaff.wisc.edu, Pediatr Clin North Am. 2001 Apr;48(2):415-23.

Table 2 shows that human milk will not meet the DRI for all vitamins in breastfeeding infants. The most glaring discrepancy between intake and the RDA is for vitamin D, although, as discussed, infants may synthesize this from sunlight exposure. Vitamin K must be given in the newborn period. Deficiencies of other vitamins are rare, especially if mothers are nourished adequately. In conclusion, in healthy, breastfed infants of well-nourished mothers, there is little risk for vitamin deficiencies and the need for vitamin supplementation is rare. The exceptions to this are a need for vitamin K in the immediate newborn period and vitamin D in breastfed infants with dark skin or inadequate sunlight exposure.

24) Do breast and bottle fed babies require vitamin supplements?
Orzalesi M, Acta Paediatr Scand Suppl. 1982;299:77-82.

In the present stage of knowledge, the following approach to vitamin supplementation seems reasonable. Breast-fed full-term infants should be supplemented with vitamin D (400 I.U./day). Supplementation of bottle-fed infants will depend upon the vitamin content of the formula which is being used. Pre-term and LBW infants may need higher amounts of vitamin D (800-1 000 I.U./day) and should be supplemented with vitamin E (1-2 I.U./day), C (50 mg/day), B6 (30-60 mcg/day) and folic acid (50-100 mcg/day) when they are being fed formulas with high amounts of PUFA and proteins or with iron.

25)Seasonal differences in serum vitamin D binding protein in exclusively breast-fed infants: negative relationship to sunshine exposure and 25-hydroxyvitamin D.
Specker BL, Tsang RC, Ho M, Buckley D, J Pediatr Gastroenterol Nutr. 1986 Mar-Apr;5(2):290-4.

Vitamin D binding protein (DBP) is the major carrier for vitamin D and its metabolites in serum. DBP increases in pregnancy and decreases in cirrhosis; no seasonal variation has been reported in adults. We observed significant seasonal differences in 41 exclusively breast-fed infants who were less than 6 months of age. Winter DBP concentrations exceeded summer DBP concentrations: 398 +/- 22 versus 297 +/- 20 micrograms/ml (mean +/- SEM). The mean concentration for spring and fall was 329 +/- 25 micrograms/ml. Maternal DBP concentrations did not differ by season. A sunshine exposure score, previously verified, was used to document time and body surface exposed to the sun. DBP was inversely related to sun exposure (r = -0.46, p = 0.005). Infant DBP was significantly and negatively correlated with 25-hydroxyvitamin D concentrations (r = - 0.38, p = 0.02). We speculate that serum DBP fluctuations are a response to varying vitamin D needs: increased serum DBP occurs in low vitamin D status to maximize uptake of vitamin D from skin.

26) Low bone mineral content and high serum osteocalcin and 1,25-dihydroxyvitamin D in summer- versus winter-born newborn infants: an early fetal effect?
Namgung R, Tsang RC, Specker BL, Sierra RI, Ho ML, Perinatal Research Institute, University of Cincinnati College of Medicine, Ohio, J Pediatr Gastroenterol Nutr. 1994 Aug;19(2):220-7.

Seasonal differences in bone mineral indices have not been studied in newborn infants. In adults, indicators of bone metabolism may show seasonal variations. In postneonatal infants and possibly in adults, vitamin D metabolism shows seasonal variations. We hypothesized that in winter-born infants, the bone mineral content is low and serum osteocalcin is high, related to increased bone turnover and high serum 1,25-dihydroxyvitamin D [1,25(OH)2D]. We studied 246 healthy, term appropriate-for-gestation infants in winter (January through March; 140 children) and summer (July through September; 106 children). The bone mineral content (BMC) of the one-third distal radius was measured before 3 days of age by photon absorptiometry. Significant seasonal differences were found: summer-born infants had significantly lower BMC, higher serum osteocalcin and 1,25(OH)2D, and lower serum total calcium than winter-born infants. Seasonal differences in BMC remained significant after adjusting for race and sex. BMC was not correlated with serum biochemical measures. Thus, summer-born newborn infants have low BMC and high serum osteocalcin and 1,25(OH)2D than winter-born infants; these findings are the opposite of adult findings.

27) Dietary vitamin D: is it necessary?
Lawson DE, J Hum Nutr. 1981 Feb;35(1):61-3.

A fuller understanding of the factors affecting vitamin D utilisation is needed to completely explain rickets and osteomalacia. The cause of many, if not most, cases in Britain is not to be found in the inadequacy of dietary vitamin D or sunlight exposure. Attention is drawn to the need to ensure that all groups at risk, eg pregnant women, receive the recommended vitamin D supplements