Asymptomatic rickets in adolescent girls.

OBJECTIVE: Inadequate sunlight exposure and calcium intake during rapid growth at puberty lead to hypocalcemia, hypovitaminosis D and eventually to overt rickets. To determine serum biochemical findings of rickets in healthy 11-15 yr old girls, the effect of sunlight exposure and oral vitamin D supplementation on serum 25- hydroxy vitamin D and calcium administration in girls with abnormal findings during December 2002 through March 2003 in Tehran, Iran. METHODS: Healthy middle school girls were selected for estimation of vitamin D, calcium and phosphorus intake by a three-day food recall. And measurement of serum calcium, phosphorus, parathyroid hormone, alkaline-phosphatase and 25- hydroxyvitamin D concentration. The girls with abnormal findings divided in two groups. Hypovitaminosis D girls subdivided into two groups, supplementary sunlight exposure and vitamin- D administrated for them and calcium administration for the second group for 20 days. RESULTS: Of 414 girls, the mean daily vitamin D acquirement and calcium intake were 119 +/- 52 IU and 360 +/- 350 mg among all girls respectively. Mean serum 25-hydroxyvitamin D with two or more abnormal biochemical findings in 15 (3.6%) girls (group I) were 7.8 ng/ml and alkaline phosphatse with normal or low calcium in 29 (7%) girls (group II) was 1187 IU/L. Mean serum calcium was 8.2 mg % in 8 of 29 girls. Serum 25- hydroxyvitamin D before and after sunlight exposure was 7.1 +/- 1.9 ng/ml and 13.9 +/- 2.4 ng/ml and vitamin D administration was 7.4 +/- 1.8 ng/ml (group Ia) and 27.9 +/- 4.2 ng/ml (group Ib) respectively. Serum alkaline phosphatase before and after calcium administration were 1187 IU/L and 666 IU/L respectively. CONCLUSION: We conclude that low daily calcium intake and vitamin D acquirement are two important problems in Iranian girls during rapid growth at puberty; therefore, for prevention of overt rickets calcium and vitamin D Supplementation appear to be necessary.

Hypocalcemia in healthy young girls in Tehran.

BACKGROUND: This study was performed in an attempt to assess serum calcium, phosphorus, and alkaline phosphatase in adolescent girls and calcium supplementation in subjects with abnormal serum findings. METHODS: A randomized, cross-sectional, cluster sampling, prospective, and descriptive trial was conducted from January through March 2003 for measurement of serum calcium, phosphorus, and alkaline phosphatase. The study group consisted of healthy girl students aged 11 - 15 years, from various areas of Tehran, Iran. Supplementary calcium tablets (2000 mg per day) were prescribed for 20 days for girls with low or normal serum calcium and raised alkaline phosphatase concentration. RESULTS: Of 414 girls who were evaluated, 29 (7%) had low or normal serum calcium and raised alkaline phosphatase concentration, with other normal findings. The mean serum calcium and alkaline phosphatase in these girls were 9.4 +/- 0.4 mg% and 1168 +/- 156 IU/L, respectively. The mean serum calcium in 8 (27.58%) of these 29 girls were 8.02 +/- 0.3 mg%. The serum calcium and alkaline phosphatase after calcium supplementation were 9.6 +/- 0.9 mg% and 666 +/- 310 IU/L, respectively, with a significant (P < 0.05) difference existing in serum alkaline phosphatase concentration among girls before and after supplementation. The serum phosphorus concentration in all girls was normal. CONCLUSION: Hypocalcemia is common in adolescent girls, which is among the subtle biochemical findings of rickets during the rapid growth period and may progress into symptomatic rickets.

Impact of dietary and lifestyle on vitamin D in healthy student girls aged 11-15 years.

OBJECTIVE: To study daily intake of calcium, phosphorus and vitamin D, to determine the biochemical findings of rickets and the effect of sunlight exposure and vitamin D supplementation in school girls with hypovitaminosis D. METHODS: A cross-sectional study was conducted on school girls aged 11-15 years selected randomly from various areas of Tehran, Iran. Dietary information and amount of sunlight exposure were estimated by a 7 day recalling method using self-reported questionnaire. Hypovitaminosis D defined as low serum 25-hydroxyvitamin D concentration with two or more others abnormal biochemical findings. Girls with hypovitaminoses D were randomly divided into two groups. The faces and hands of girls in group 1 were exposed to sunlight for one hour per day for twenty days, while those in group 2 were administered vitamin D capsules, 50,000 IU per day for the same period. RESULTS: four-hundred fourteen girls evaluated, mean daily calcium intake, sunlight exposure and vitamin D acquirement were 360 mg, 10 minutes and 119 IU, respectively. Mean serum 25-hydroxyvitamin D concentration was 30 ng/ml among all girls whereas in 15 (3.63%) of 414 girls was 7.8 ng/ml. Abnormal biochemical findings in these girls included hypocalcemia (n=4), hypophosphatemia (n=5), raised serum alkaline phosphatase (n=13), and parathyroid hormone (n=15). After intervention, mean serum 25-hydroxyvitamin D concentration in sunlight exposure (n=8) and vitamin D (n=7) supplementation increased to 14.4+/-4 ng/ml and 23+/-4 ng/ml respectively. There was a significant difference between the two groups (p<0.05). CONCLUSION: Vitamin D deficiency developed in rapid growth period of girls without clear clinical rickets in sunny temperate climate city in Iran which vitamin D supplementation improved biochemical findings better than sunlight exposure.