case series: Vitamin D deficiency in exclusively breastfed term and late preterm neonates

Yıl 2013, Cilt: 5 , - , 27.06.2013

Prarthana Karumbaiah , Pradeep G.c.m

Öz

Vitamin D plays an integral role in calcium metabolism. Vitamin D levels in neonates are determined by in-utero transfer of vitamin D and through breast milk. This in turn depends on the maternal stores of vitamin D. We present case series of term and late preterm neonates who were admitted to tertiary level neonatal ICU with vitamin D deficiency manifesting as symptomatic hypocalcemia.

Anahtar Kelimeler

maternal vitamin D deficiency, neonatal vitamin D deficiency

Kaynakça

• range 4-3 2-1 4-7 1-50 30-100 30-100 Baby 1 2 1 2 7 11 11 Baby 2 4 77 4 5 7 2 Baby 3 6 4 8 109 12 6 Baby 4 6 64 7 195 61 17 Baby 5 7 86 3 7 07 52 Baby 6 6 19 5 1 42 23 Baby 7 0 01 7 4 76 26 rocalterol 0.25mg ¼ sachet daily till the serum calcium was more than 8.5 mg/dl. Treatment was initiated for the mothers too, with oral vitamin D3 (60000 IU) per week for 8 weeks. The laboratory investigations done after 8 weeks showed normal levels of serum calcium and 25 hydroxyvitaminD3 both in the mother and the baby. Discussion
• The present case series included term and late preterm babies exclusively on breastfeeding. Physiologically, in the healthy term neonates too, there is a decline in the serum calcium levels for the first 24-48 hours, the nadir usually 7.55mg/dl. Thereafter, progressively it rises to the mean values. However, with vitamin D deficiency, the decline in serum calcium levels is accelerated [ 3]. Vitamin D is synthesised in the skin when its precursor, 7-dehydrocholesterol is exposed to the ultraviolet rays from the sun. This is hydroxylated to 25hydroxyvitamin D in the liver and to 1,25 dihydroxyvitamin D in the kidney which enhances the absorption of calcium predominantly from the intestines and also reabsorption from the kidneys when the serum calcium levels decline. People living in tropical countries as in India, which extends from 8.4º N latitude to 37.6° N latitude has majority of its population living in areas receiving ample sunlight throughout the year. Hence, it is assumed that these people have less incidence of vitamin D deficiency including pregnant women [4]. But, the amount of ultraviolet exposure available for the synthesis of vitamin D depends on the amount of skin exposed to sunlight especially at noon, amount of skin pigmentation, body mass, degree of latitude, season, the amount of cloud cover, the extent of air pollution, and the extent of UV protection, including clothing and sunscreens [5,6] In the present case series, all the mothers gave history of using sunscreen creams and decreased exposure to sunlight, though we did not calculate the exact sunshine exposure. This could have attributed to vitamin D deficiency seen in these mothers. There is a close relationship between the maternal and neonatal vitamin D levels. Vitamin D levels in neonates depend on the antenatal transfer of the vitamin from mother and postnatal transfer through the breast milk and exposure to sunlight. Vitamin D in breast milk relates to mothers’ vitamin D intake, skin pigmentation and sunlight exposure. This implies that babies born to mothers with vitamin D deficiency are very likely to develop vitamin D deficiency unless supplemented from outside or adequately exposed to sunlight which is often not practical during early infancy. The breast milk of vitamin D replete mothers contains only about 15-75 IU/L of vitamin D per litre which is insufficient to meet the recommended RDA of vitamin D (400 IU/L) [79]. Postnatal exposure to sunlight is an important source of vitamin D synthesis in neonates. Exposure to the sunlight in neonates is unlikely in the early period of life. The above factors discussed could have led to Vitamin D deficiency seen in neonates in this case series. Most of these neonates had refractory hypocalcemia and did not respond to routine calcium supplementation. This could be explained by the role of vitamin D3 in absorption of calcium. Though the neonates had different presentations giving a clue to the diagnosis, the mothers were asymptomatic. Our cases are an eye opener to the possibility of higher prevalence of maternal vitamin D deficiency and in turn neonatal vitamin D deficiency in the tropical countries. Term/Preterm neonates presenting as early onset hypocalcemia refractory to treatment should hence be investigated further for associated vitamin D deficiency. References Alok Sachan, Renu Gupta, Vinita Das, Anjoo Agarwal, Pradeep K Awasthi, and Vijayalakshmi Bhatia. High prevalence of vitamin D deficiency among pregnant women and their newborns in northern India. Am J Clin Nutr 2005;81: 1060-1064 Vandana Jain, Nandita Gupta, Mani Kalaivani, Anurag Jain, Aditi Sinha & Ramesh Agarwal. Vitamin D deficiency in healthy breastfed term infants at 3 months & their mothers in India: Seasonal variation & determinants. Indian J Med Res 2011;133: 267-273 Cloherty JP, Eichenwald EC, Hansen AR, Stark AR. Manual of neonatal care, 7th edition, Lippincott Williams and Wilkins, Philadelphia, ;299. Hodgkin P, Kay GH, Hine PM, et al. vitamin D deficiency in Asians at home and in Britain. Lancet 1973; 167-171. Chen TC, Chimeh F, Lu Z, Mathieu J, Person KS, Zhang A et al. Factors that influence the cutaneous synthesis and dietary sources of vitamin D. Arch Biochem Biophy 2007;460:213-217 William G, Tsiaras and Martin A, Weinstock. Factors influencing Vitamin D status. Acta Derm Venereol 2011;91:115-124 Vitamin and mineral supplement needs in normal children in the United States. Pediatrics 1980; 60:1010-20 Reeve LE, Chesney RW, DeLuca HF. Vitamin D of human milk:identification of biologically active forms. Am J Clin Nutr 1982; 36: 122-126 Hollis BW, Roos BA, Draper HH, Lambert PW. Vitamin D and its metabolites in human and bovine milk. J Nutr 1981; 111: 12401248