Pseudohypoparathyroidism.

OBJECTIVES: To examine seasonality of 25-hydroxyvitamin D (25OH-D) levels in British preschool children and the effect of vitamin D supplementation on this. DESIGN: The National Diet and Nutrition Survey of children aged 1.5 4.5 y in Britain during 1992-3 measured dietary intakes and blood status indices, including those for vitamin D, during all four seasons. The present study addresses the seasonal dependence of the relation between vitamin D intake and status. SETTING: 100 randomly selected postcode sectors throughout Britain, whose locations were classified as (a) Scotland; (b) Northern England; (c) Central, Wales, South+SW; (d) London+SE. SUBJECTS: Of 1859 whose parents or guardians were interviewed, 1675 provided a weighed diet estimate, and blood vitamin D status (25OH-D) was measured in 756, with approximately equal numbers in each season. RESULTS: Vitamin D status is highly dependent on season: moreover, the relation between vitamin D intake and status is also seasonally dependent, being strong in the winter and negligible in the summer. During the winter, those children who had relatively low 25OH-D concentrations generally were those not receiving vitamin D supplements. Vitamin D intakes and supplement use were lower in the north than in the south of Britain. CONCLUSIONS: For British preschool children, dietary vitamin D is of much greater importance in the winter than in the summer. There is evidence of regional inequality, with lesser use of supplements in the north. Supplements are needed in the winter, to achieve satisfactory vitamin D status and minimise the risk of rickets and of poor bone health, especially in high-risk groups.

Calcifediol↗

PubMed1999

Perinatal vitamin D and calcium status of northern Canadian mothers and their newborn infants.

OBJECTIVE: This study was undertaken to examine the vitamin D and calcium status of mothers and their newborns. METHODS: The intakes of vitamin D and calcium were determined prenatally in 121 women including 33 Caucasians, 51 Inuits, and 37 Native Indians, living in the Inuvik zone of the Northwest Territories. Plasma concentrations of 25-(OH)-D and calcium were also measured in mothers as well as in their offspring at delivery. RESULTS: The daily mean vitamin D intake of native mothers, including Inuits and Indians, with (8.1+/-5.5 microg) and without supplements (3.4+/-2.5 microg) was significantly lower than that of non-native mothers (13.2+/-5.9 microg and 5.8+/-4.3 microg, respectively). According to the predicted prevalence of low vitamin D intake, there existed a higher risk of vitamin D deficiency without supplementation in both native (88.6% vs 48.4%) and non-native (63.5% vs. 15.1%) mothers. The trend for calcium intakes with and without supplementation was similar to vitamin D intake. At the point of delivery, the plasma levels of 25-(OH)-D were lower in native mothers (50.1 19.3 nmol/L) and their offspring (34.2+/-13.1 nmol/L) than their counterparts (59.8+/-29.4 nmol/L and 41.4+/-23.5 nmol/L, respectively). Its plasma levels in newborn infants averaged only 67% of their mothers. None of these infants showed clinical evidence of vitamin D deficiency. In fact, their plasma calcium levels were significantly higher than their mothers. CONCLUSIONS: Plasma 25-(OH)-D concentrations of 60 to 70% of maternal levels may represent a "normal" range for newborn infants. However, a supplementation in native northern Canadian mothers during pregnancy and in their neonates during infancy may have a role to play in the prevention of vitamin D deficiency.

Calcifediol↗