25-Hydroxycholecalciferol serum levels in breast-fed infants

Prenatal vitamin D supplementation and infant vitamin D status in Bangladesh

OBJECTIVE

To determine the effect of prenatal maternal vitamin D supplementation on infant vitamin D status in a tropical region where vitamin D supplementation is not routine.

DESIGN

A prospective observational follow-up of a randomized trial.

SETTING

Maternal-child health facility in Dhaka, Bangladesh (23°N).

SUBJECTS

Infants born to pregnant women (n 160) randomized to receive 875 µg (35 000 IU) cholecalciferol (vitamin D3) per week (VD) or placebo (PL) during the third trimester were followed from birth until 6 months of age (n 115). Infant serum 25-hydroxyvitamin D concentration (25(OH)D) was measured at <1, 2, 4 and 6 months of age.

RESULTS

Mean infant 25(OH)D was higher in the VD v. PL group at <1 month of age (mean (sd): 80 (20) nmol/l v. 22 (18) nmol/l; P<0·001), but the difference was attenuated by 2 months (52 (19) nmol/l v. 40 (23) nmol/l; P=0·05). Groups were similar at 4 months (P=0·40) and 6 months (n 72; P=0·26). In the PL group, mean infant 25(OH)D increased to 78 (95 % CI 67, 88) nmol/l by 6 months of age (n 34). 25(OH)D was higher with infant formula-feeding and higher in summer v. winter.

CONCLUSIONS

Prenatal third-trimester vitamin D supplementation (875 µg (35 000 IU)/week) significantly ameliorated infant vitamin D status during the neonatal period when the risk of vitamin D deficiency is greatest. Further research is warranted to determine factors that contribute to the rise in 25(OH)D during the first 6 months of life among breast-fed infants in this setting.

Maternal vitamin D status: effect on milk vitamin D content and vitamin D status of breastfeeding infants

There are increasing reports of rickets and vitamin D deficiency worldwide. Breastfeeding without adequate sunlight exposure and vitamin D supplementation are the major risk factors. In view of the drive to promote and increase the rate of exclusive breastfeeding, the relationship among maternal vitamin D status, vitamin D concentration of human milk, and hence vitamin D status of breastfeeding infants deserves reassessment. This review provides current information on the interrelationship between maternal vitamin D status and the vitamin D status of the breastfeeding infant. It also reviews the results of ongoing research on the effect of high-dose maternal vitamin D supplementation alone as a possible option to prevent vitamin D deficiency in the breastfeeding mother-infant dyad.

Prevention of vitamin D deficiency in mothers and infants worldwide - a paradigm shift

Vitamin D deficiency in mothers and infants is a global health disorder despite recognition that it is preventable. Recent data support the theory that vitamin D deficiency in adults and children may increase the risk of infections and auto-immune diseases. In most cases, vitamin D deficiency is caused by sunlight deprivation and inadequate corrective vitamin D intake. There is a strong mother/infant vitamin D relationship that affects vitamin D status both in utero and in infancy. Recognition that vitamin D deficiency is a worldwide mother/infant health problem is a basis on which to modify public health strategies to reduce the burden of disease and improve maternal and child vitamin D nutrition. This review provides an update on vitamin D function and the global scope and implications of vitamin D deficiency as it relates to pregnancy and infancy. It also addresses a combined strategy to prevent vitamin D deficiency during pregnancy, lactation and infancy.

Vitamin D Status of term exclusively breastfed infants and their mothers from India

OBJECTIVES

(i) To measure 25-OH vitamin D levels in term infants at 10 weeks and 6 months and to correlate with maternal vitamin D levels at 10-week postpartum (ii) To evaluate infants at 6 months for rickets.

PATIENTS AND METHODS

A total of 179 exclusively breastfed infant-mother pairs 96 appropriate-for-gestational age (Group 1) and 83 small- for- gestational age infants (Group 2) recruited at 10 weeks. At 6 months, 52 in group 1 and 45 in group 2 were evaluated. Venous blood sample were collected at 10 weeks and 6 months in infants and at 10 weeks in mothers for calcium, phosphorus, alkaline phosphatase and 25-OH vitamin D estimation.

RESULTS

Mean 25-OH vitamin D levels of infants (n = 97) were 11.55 ± 7.17 ng/mL at 10 weeks and 16.96 ± 13.33 ng/mL at 6 months (p < 0.001). Mean vitamin D levels of infants in group 1 and group 2 did not differ at recruitment and 6 months (p > 0.05)). Maternal vitamin D levels in group 1 and group 2 were 8.89 ± 5.97 and 9.87 ± 6.44 ng/mL, respectively (p = 0.44). Significant correlation was observed between 25-OH vitamin D of infants and mothers (p < 0.05). At 10 weeks, 55.67% infants, 70% mothers and at 6 months, 44.33% infants had vitamin D < 11 ng/mL. At 6 months, 16.49% infants developed rickets.

CONCLUSIONS

Exclusively breastfed infants and their mothers are Vitamin D deficient, hence the need to improve vitamin D status.

Vitamin D nutritional status of exclusively breast fed infants and their mothers

BACKGROUND

Vitamin D nutrition has a profound effect on the development of an infant. Vitamin D status of mothers and their infants are closely correlated. While hypovitaminosis D has emerged as a significant public health problem across all age groups, there is limited information of this condition in lactating mothers and their breast fed infants.

AIM

To evaluate the vitamin D status of lactating mothers and their breast fed infants.

SUBJECTS AND METHODS

180 healthy lactating mothers and exclusively breast fed infants, 2-24 weeks old, were recruited for the study. The mother-infant pairs underwent concurrent clinical, biochemical and hormonal evaluation for calcium-vitamin D-PTH axis.

RESULTS

The mean serum 25(OH)D values in lactating mothers was 27.2 +/- 14.6 nmol/l (10.9 +/- 5.8 ng/ml), while that of their infants was 28.9 +/- 20.8 nmol/l (11.6 +/- 8.3 ng/ml). Serum 25(OH)D levels <25 nmol/l (10 ng/ml) were found in 47.8% of the mothers and 43.2% of the infants. Among these, elevated PTH levels (>54 pg/ml) were seen in 59.3% of the mothers and 69.6% of the infants. A highly significant negative correlation was found between serum 25(OH)D and PTH in mothers (r = -0.480, p = 0.01) and their infants (r = -0.431, p = 0.01). A strong positive correlation was seen of 25(OH)D levels in mother-infant pairs (r = 0.324, p = 0.001).

CONCLUSIONS

A high prevalence of vitamin D deficiency was found in lactating mothers and their exclusively breast fed infants. Infants born to mothers with hypovitaminosis D had 3.8 times higher risk of developing hypovitaminosis D as compared to those born to mothers with normal vitamin D levels.

Hypovitaminosis D and vitamin D deficiency in exclusively breast-feeding infants and their mothers in summer: a justification for vitamin D supplementation of breast-feeding infants

OBJECTIVE

To determine the prevalence of hypovitaminosis D in exclusively breast-feeding infants and their mothers in a community where maternal sunshine exposure is low.

STUDY DESIGN

Serum levels of calcium, phosphate, alkaline phosphatase, 25-hydroxy vitamin D (25-OHD), and intact parathyroid hormone were measured in 90 unsupplemented healthy term breast-feeding Arab/South Asian infants and their mothers in summer. Maternal dietary vitamin D intake was also estimated.

RESULTS

The median age of infants was 6 weeks. The median serum 25-OHD concentrations in mothers (8.6 ng/mL) and infants (4.6 ng/mL) were low, and 61% of the mothers and 82% of the 78 infants tested had hypovitaminosis D (serum 25-OHD <10 ng/mL). The infants with hypovitaminosis D had elevated serum alkaline phosphatase and a tendency to higher serum intact parathyroid hormone levels. The average daily maternal vitamin D intake from commercial milk was 88 IU.

CONCLUSIONS

Hypovitaminosis D is common in summer in exclusively breast-feeding infants and their mothers. The results provide justification for vitamin D supplementation of breast-feeding infants and mothers in the United Arab Emirates. Low vitamin D intake probably contributed to low maternal vitamin D status.

Severe nutritional deficiencies in toddlers resulting from health food milk alternatives

It is widely appreciated that health food beverages are not appropriate for infants. Because of continued growth, children beyond infancy remain susceptible to nutritional disorders. We report on 2 cases of severe nutritional deficiency caused by consumption of health food beverages. In both cases, the parents were well-educated, appeared conscientious, and their children received regular medical care. Diagnoses were delayed by a low index of suspicion. In addition, nutritional deficiencies are uncommon in the United States and as a result, US physicians may be unfamiliar with their clinical features. Case 1, a 22-month-old male child, was admitted with severe kwashiorkor. He was breastfed until 13 months of age. Because of a history of chronic eczema and perceived milk intolerance, he was started on a rice beverage after weaning. On average, he consumed 1.5 L of this drink daily. Intake of solid foods was very poor. As this rice beverage, which was fallaciously referred to as rice milk, is extremely low in protein content, the resulting daily protein intake of 0.3 g/kg/day was only 25% of the recommended dietary allowance. In contrast, caloric intake was 72% of the recommended energy intake, so the dietary protein to energy ratio was very low. A photograph of the patient after admission illustrates the typical features of kwashiorkor: generalized edema, hyperpigmented and hypopigmented skin lesions, abdominal distention, irritability, and thin, sparse hair. Because of fluid retention, the weight was on the 10th percentile and he had a rotund sugar baby appearance. Laboratory evaluation was remarkable for a serum albumin of 1.0 g/dL (10 g/L), urea nitrogen <0.5 mg/dL (<0.2 mmol/L), and a normocytic anemia with marked anisocytosis. Evaluation for other causes of hypoalbuminemia was negative. Therapy for kwashiorkor was instituted, including gradual refeeding, initially via a nasogastric tube because of severe anorexia. Supplements of potassium, phosphorus, multivitamins, zinc, and folic acid were provided. The patient responded dramatically to refeeding with a rising serum albumin and total resolution of the edema within 3 weeks. At follow-up 1 year later he continued to do well on a regular diet supplemented with a milk-based pediatric nutritional supplement. The mortality of kwashiorkor remains high, because of complications such as infection (kwashiorkor impairs cellular immune defenses) and electrolyte imbalances with ongoing diarrhea. Children in industrialized countries have developed kwashiorkor resulting from the use of a nondairy creamer as a milk alternative, but we were unable to find previous reports of kwashiorkor caused by a health food milk alternative. We suspect that cases have been overlooked. Case 2, a 17-month-old black male, was diagnosed with rickets. He was full-term at birth and was breastfed until 10 months of age, when he was weaned to a soy health food beverage, which was not fortified with vitamin D or calcium. Intake of solid foods was good, but included no animal products. Total daily caloric intake was 114% of the recommended dietary allowance. Dietary vitamin D intake was essentially absent because of the lack of vitamin D-fortified milk. The patient lived in a sunny, warm climate, but because of parental career demands, he had limited sun exposure. His dark complexion further reduced ultraviolet light-induced endogenous skin synthesis of vitamin D. The patient grew and developed normally until after his 9-month check-up, when he had an almost complete growth arrest of both height and weight. The parents reported regression in gross motor milestones. On admission the patient was unable to crawl or roll over. He could maintain a sitting position precariously when so placed. Conversely, his language, fine motor-adaptive, and personal-social skills were well-preserved. Generalized hypotonia, weakness, and decreased muscle bulk were present. Clinical features of rickets present on examination included: frontal bossing, an obvious rachitic rosary (photographed), genu varus, flaring of the wrists, and lumbar kyphoscoliosis. The serum alkaline phosphatase was markedly elevated (1879 U/L), phosphorus was low (1.7 mg/dL), and calcium was low normal (8.9 mg/dL). The 25-hydroxy-vitamin D level was low (7.7 pg/mL) and the parathyroid hormone level was markedly elevated (114 pg/mL). The published radiographs are diagnostic of advanced rickets, showing diffuse osteopenia, frayed metaphyses, widened epiphyseal plates, and a pathologic fracture of the ulna. The patient was treated with ergocalciferol and calcium supplements. The published growth chart demonstrates the dramatic response to therapy. Gross motor milestones were fully regained within 6 months. The prominent neuromuscular manifestations shown by this patient serve as a reminder that rickets should be considered in the differential diagnosis of motor delay. (ABSTRACT TRUNCATED)

Nutritional vitamin D deficiency rickets in Sudanese children

Nutritional vitamin D deficiency rickets was established in 41 Sudanese children aged from 3 months to 7 years by clinical, radiological and therapeutic response supported by biochemical investigations. There were 25 boys and 16 girls, of whom 42% were infants of less than 1 year. Forty-seven per cent of rachitic children were underweight. Six infants had early rickets with no bony swellings but had other clinical features and radiological evidence of rickets. One of them, aged 3 months, presented with hypocalcaemic convulsions. Three children had icthyosis. Serum alkaline phosphatase was raised in 75%, hypophosphataemia occurred in 68% and hypocalcaemia in 54% of patients. Anaemia, mostly hypochromic, was detected in 79%. Possible causes were poor socio-economic background, inadequate dietary intake in both mothers and children, prolonged breastfeeding, prematurity, limited sun exposure and type of residence. Nutritional vitamin D deficiency rickets should be looked for in Sudanese children, especially in preterms and in those living in flats.

Nutritional rickets

Nutritional rickets was once felt to be a disease of the past. In recent years, dietary patterns and the prevalence of unsupplemented breast feeding has led to a mild resurgence in rickets. The cases presented show a wide spectrum of nutritional disease, illustrating the common risk factors, the usefulness of vitamin-D metabolite assays in making a definitive diagnosis, and the response to vitamin-D therapy.

Vitamin D metabolism, mineral homeostasis, and bone mineralization in term infants fed human milk, cow milk-based formula, or soy-based formula

The purpose of this study was to evaluate mechanisms of mineral homeostasis and mineralization in term infants with recommended vitamin D intakes. Infants fed human milk (nine), cow milk-based formula (11), or soy-based formula (11) were studied at 2 weeks and at 2, 4, 6, 9, and 12 months of age. While receiving 400 IU of vitamin D, all infants maintained serum vitamin D concentrations higher or equal to normal adult concentrations, and serum 25-hydroxyvitamin D levels were maintained at or above normal adult levels. Serum 1,25-dihydroxyvitamin D concentrations were higher than those of adults in the formula-fed but not in the human milk-fed infants. Serum calcium and phosphorus values were similar in all groups; however, urine phosphorus excretion and urine calcium excretion were adjusted to intakes. Serum parathyroid hormone values were normal in all groups. Bone mineral content significantly increased with age similarly in all groups; however, an apparent plateau occurred at 6 months of age in all groups. Bone width steadily increased with age. Taken as a whole, these data suggest that the vitamin D-sufficient term infant fed human milk, cow milk-based formula, or the soy-based formula studied can regulate mineral metabolism within acceptable physiologic limits to attain similar levels of serum minerals and bone mineral content.

Maternal compared with infant vitamin D supplementation

Vitamin D metabolites were studied in mother-infant pairs at delivery and eight and 15 weeks after that to evaluate the possibility of vitamin D supplementation of infant through the mother. Healthy mothers (n = 49) delivering in January received daily either 2000 IU (group 1), 1000 IU (group 2), or no (group 3) vitamin D. Their infants were exclusively breast fed, and those in group 3 received 400 IU of vitamin D a day. After eight weeks of lactation the infantile vitamin D concentrations were similar in groups 1 and 3 but significantly lower in group 2. The serum 24,25-dihydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations were also lower in group 2. The mean mineral, parathyroid hormone, and alkaline phosphatase values showed no intergroup differences at any point. No infants showed any clinical or biochemical signs of rickets, and their growth was equal. In conclusion, a daily postpartum maternal supplementation with 2000 IU of vitamin D, but not with 1000 IU, seems to normalise the vitamin D metabolites of breast fed infants in winter. Maternal safety with such supplementation over prolonged periods, however, should be examined.

Vitamin D deficiency in mothers of rachitic infants

The existence of nutritional deficiency rickets among infants in sunny Riyadh was confirmed radiologically. Most of the rachitic infants were breast-fed, some received unsupplemented infant feeding formulae, and all live in an environment that is devoid of sunlight. Their mean age at the time of onset was 10.5 months. 25-Hydroxyvitamin D (25OHD) levels were found to be low in mothers of the rachitic infants. This maternal deficiency as a factor in pathogenesis of rickets in the infant is discussed. Proposals are made to prevent the occurrence of rickets on this scale.

Serum concentrations of vitamin D metabolites in exclusively breast-fed infants at 70 degrees north

The effect of prolonged breast-feeding on the serum concentrations of vitamin D metabolites, calcium, phosphate, and alkaline phosphatase was studied longitudinally in 7 infants from Northern Norway. They were exclusively breast-fed for a median of 7 1/2 months. Three of the mothers were supplemented with vitamin D throughout lactation. All but one of the infants had 25-hydroxyvitamin D (25-OHD) levels in the rachitic range (less than 20 nmol/l) on at least one occasion. Vitamin D supplementation of the mother had no apparent effect on the infants' 25-OHD levels, but the values increased during summer. The infant who had the lowest 25-OHD levels also had decreased 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentrations, while the others maintained 1,25-(OH)2D levels within normal limits. 24,25-(OH)2D concentrations were undetectable when the 25-OHD levels were below 35 nmol/l, but the two metabolites were closely correlated for higher values of 25-OHD. Low 25-OHD levels were associated with decreased phosphate concentrations at 6 months. The calcium levels were normal throughout the study period of one year, as were all but two of the alkaline phosphatase values. Although none of the infants had clinical or biochemical evidence of rickets, the results suggest that the vitamin D supply from human milk is inadequate, and that routine vitamin D supplementation is advisable for breast-fed infants who are deprived of sunlight exposure.

Plasma concentrations of vitamin D metabolites in unsupplemented breast-fed infants

Plasma concentrations of the vitamin D metabolites 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D and 25,26-dihydroxyvitamin D were determined in 12 solely breast-fed infants 4 days and 6 weeks after birth. They were not exposed to sunlight, but the mothers received an average of 600 IU vitamin D2 per day during the study period. The mothers' 25-hydroxyvitamin D levels did not change significantly (medians 42 and 58 nmol/l), but the median level dropped from 26 to 15 nmol/l in the infants (P less than 0.001). There was a close correlation between maternal and infant levels at 4 days (r = 0.95). The babies with the highest initial levels showed the most marked decrease by 6 weeks. The median concentrations of 24,25-dihydroxyvitamin D and 25,26-dihydroxyvitamin D decreased similarly from 1.7 to 0.8 and 0.63 to 0.35 nmol/l respectively, (P less than 0.001). The 1,25-dihydroxyvitamin D levels were within normal limits as were plasma calcium, phosphorus, and alkaline phosphatase. 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.

The relationship of adequate and excessive intake of vitamin D to health and disease

Vitamin D is required for intestinal calcium and phosphorus absorption, kidney functions, bone synthesis, and possible vital functions in several other target tissues. Active forms of vitamin D are generated by hydroxylations, first in the liver and second in the kidney. The requirement for vitamin D is normally met by its synthesis in the skin. Inadequate skin exposure to sunlight, dark-pigmented skin, and a northern geographical latitude make some individuals susceptible to a deficiency. In the United States, various foods are fortified with vitamin D to ensure that such deficiencies do not occur. As a result, most individuals consume and synthesize more vitamin D than they require. Vitamin D is a toxic compound, and excessive amounts can cause soft-tissue calcification. We have suggested a mechanism by which this calcification might occur. There is a narrow leeway between the amount required and that initiating tissue damage. As most individuals appear to be at risk of obtaining too much vitamin D rather than too little, we suggest that fortification of foods with vitamin D should be curtailed, preferably abolished, that excessive fortification of animal foods be reduced to the level required, and that the use of dietary supplements be restricted. Populations at risk could be monitored closely and counseled to prevent vitamin D deficiency.

Maternal-infant vitamin D relationships during breast-feeding

To evaluate the effect of maternal dietary vitamin D intake on infant vitamin D status in a country with a temperate climate, but where the commercial milk supply is not vitamin D fortified, this randomized, double-blind study was conducted on term mother-infant pairs during the winter months. Well-nourished, white nursing mothers were given a placebo, 500 IU vitamin D/day or 1,000 IU vitamin D/day; their infants were not given supplemental vitamin D. After six weeks, mothers receiving supplemental vitamin D had higher levels of 25-hydroxyvitamin D than had mothers receiving placebo. A direct relationship was observed between maternal and infant levels of 25-hydroxyvitamin D at six weeks, implying that maternal vitamin D intake directly affects the vitamin D concentration in breast milk. A control group of infants who had received 400 IU vitamin D/day had even higher concentrations of 25-hydroxyvitamin D, suggesting that infant supplementation with vitamin D is more efficacious than maternal supplementation. Despite the favorable climate in South Africa, during winter breast-fed infants have low serum vitamin D values if maternal dietary vitamin D intake is low.

Vitamin D metabolites in human milk

The concentrations of unconjugated 25-OHD, 24, 25(OH)2D, and 1,25(OH)2D were measured in human milk by competitive protein-binding radioassays following successive preparative Sephadex LH-20 chromatography and HPLC. The mean (+/- SE) concentration of 25-OHD was 0.37 +/- 0.03 ng/ml, of 24,25(OH)2D was 24.8 +/- 1.9 pg/ml, and of 1,25(OH)2D was 2.2 +/-0.1 pg/ml. The concentration of 25-OHD3 in milk as determined by HPLC and UV detection at 254 nm was 0.27 +/- 0.08 ng/ml. The milk concentrations of vitamin D metabolites did not correlate with the maternal serum 25-OHD levels. The total amounts of unconjugated vitamin D metabolites correspond to the known low bioassayable vitamin D antirachitic activity in human milk.

Seasonal changes in perinatal vitamin D metabolism: maternal and cord blood biochemistry in normal pregnancies

Two groups of white, primiparous women and their babies were studied: one group in April 1979 and the other in September 1979. They were selected to be as near normal as possible. In each case maternal and cord blood samples were taken at delivery and analysed for serum 25-hydroxycholecalciferol (25-OHD), calcium, magnesium, phosphate, alkaline phosphatase, total protein, and albumin. Follow-up was by questionnaire at 6 weeks. The study showed a highly significant increase in maternal and cord serum 25-OHD levels in September. The few mothers who had taken vitamin D supplements had significantly higher serum 25-OHD values. Some of the unsupplemented women studied in April had low serum 25-OHD levels suggesting that oral vitamin D supplements should be given to pregnant white women in Britain, at least during the winter.