Pregnancy support - Treatment

Vitamin D - updated: 03 November 2008

Prenatal and infant predictors of bone health: the influence of vitamin D

Am J Clin Nutr. 2004 Dec;80(6 Suppl):1748S-51S

Pawley N, Bishop NJ.

Vitamin D is essential for the health of pregnant women and their infants. Vitamin D insufficiency and deficiency during pregnancy are reflected in lower maternal weight gain and biochemical evidence of disturbed skeletal homeostasis in the infant, with, in extreme situations, reduced bone mineralization, radiologically evident rickets, and fractures. Populations at risk for vitamin D deficiency are those for which, for environmental, cultural, or medical reasons, exposure to sunlight is poor and the dietary intake of vitamin D is low. The infants born in such populations have low vitamin D stores and may receive little additional vitamin D if they are breast-fed without supplements for long periods. In the short term, lack of vitamin D supplementation in infancy leads to biochemical disturbances, reduced bone mineralization, slower growth, and eventual alterations in bone shape and increased risk of fracture, the hallmarks of rickets. In the longer term, lack of vitamin D supplementation may result in reduced bone size and mass during childhood and an increased risk of type 1 diabetes mellitus. Clear recommendations are needed regarding the intake of vitamin D during pregnancy and infancy. Such recommendations should be based on functional outcomes, rather than biochemical measurements, so that the medical problems resulting from the lack of this essential nutrient can be overcome.

Publication Types:

• Review

Vitamin D supplementation during pregnancy: effect on neonatal calcium homeostasis

J Pediatr. 1986 Aug;109(2):328-34

Delvin EE, Salle BL, Glorieux FH, Adeleine P, David LS.

We assessed whether modification of vitamin D nutritional status during the last trimester of pregnancy affects maternal and neonatal calcium homeostasis. At the end of the first trimester, 40 pregnant women were randomly assigned to either of two groups, and blood taken to assess the basal values of Ca, Pi, Mg, iPTH, 25-OHD, and 1,25(OH)2D. From the sixth month on, group 1 (+D) received 1000 IU vitamin D3 daily; group 2 (-D) served as control. At the time of delivery, maternal serum 25-OHD was higher in the +D group (P less than 0.0005). Ca, Pi, iPTH, and 1,25(OH)2D were not affected. At term, venous cord 25-OHD levels were also higher in the +D group (P less than 0.0005), and 1,25(OH)2D levels slightly lower (P less than 0.05), but neither Ca, Pi, nor iPTH differed between the two groups. Serum CaT dropped significantly (P less than 0.002) at 4 days of age in the infants from both groups, although to a lesser extent in these from the +D group (P less than 0.05). Circulating iPTH increased in both groups. Serum 25-OHD remained low in the -D group, and dropped slightly in the +D group; 1,25(OH)2D remained stable during the first 4 days of life in the -D group, and increased in the +D group (P less than 0.001). Our data demonstrate the importance of providing adequate maternal vitamin D stores to ensure better perinatal handling of calcium. This is of particular importance for populations at risk for hypovitaminosis D.

Publication Types:

• Randomized Controlled Trial

Vitamin D supplements in pregnant Asian women: effects on calcium status and fetal growth

Br Med J. 1980 Mar 15;280(6216):751-4

Brooke OG, Brown IR, Bone CD, Carter ND, Cleeve HJ, Maxwell JD, Robinson VP, Winder SM.

In a double-blind trial of vitamin D supplements in pregnant Asian women calciferol (ergocalciferol, 1000 IU/day) was administered to 59 women and placebo to 67 controls during the last trimester. The two groups had similar distributions of maternal age, height, parity, number of vegetarians, countries of origin, and sex and gestation of the infants. At entry to the trial maternal serum 25-hydroxy vitamin D (25-OHD) concentrations were low in both treatment and control groups and significantly lower in vegetarians than non-vegetarians. Mothers in the treatment group gained weight faster in the last trimester than those in the control group, and at term they and their infants all had adequate plasma 25-OHD concentrations, Mothers and infants in the control group, however, had low plasma concentrations of 25-OHD and calcium and raised plasma alkaline phosphatase (bone isoenzyme) activity. Five of these infants developed symptomatic hypocalcaemia. Almost twice as many infants in the control group were small for gestational age (29% v 15%), but there were no significant differences between the two groups of infants in antropometric measurements. Infants in the control group, however, had larger fontanelles, suggesting impaired ossification of the skull. Because of the benefits to mothers and infants in the treatment group and the absence of side effects, vitamin D supplements should be given to all pregnant Asian women in the United Kingdom.

Publication Types:

• Randomized Controlled Trial

Altered vitamin-D metabolism in pregnancy

Lancet. 1977 Jan 29;1(8005):222-5

Turton CW, Stanley P, Stamp TC, Maxwell JD.

Low levels of plasma-25-hydroxy-vitamin-D (25-OHD) (less than 16 nmol/1) were found in 33% of a group of pregnant women studied in South London. Non-White women in the last 10 weeks of pregnancy had significantly reduced levels compared with non-pregnant controls (P less than 0.02). Plasma-25-OHD was unrelated to dietary vitamin-D intake, age, parity, social class, plasma-calcium, and plasma-albumin. Reduction of plasma-25-OHD could contribute to the fall in plasma-calcium during pregnancy, and may result from enhanced maternal metabolism or increased utilisation of vitamin D by the fetus.

Publication Types:

• Review