Vitamin D status and its association with parathyroid hormone concentrations in women of child-bearing age living in Jakarta and Kuala Lumpur.
OBJECTIVE
To describe the vitamin D status of women living in two Asian cities,--Jakarta (6 degrees S) and Kuala-Lumpur (2 degrees N), to examine the association between plasma 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations, and to determine a threshold for plasma 25-hydroxyvitamin D above which there is no further suppression of PTH. Also, to determine whether dietary calcium intake influences the relationship between PTH and 25-hydroxyvitamin D.


METHODS
Cross-sectional.


METHODS
Jakarta, Indonesia and Kuala Lumpur, Malaysia.


METHODS
A convenience sample of 504 non-pregnant women 18-40 years.


METHODS
Plasma 25-hydroxyvitamin D and PTH.


RESULTS
The mean 25-hydroxyvitamin D concentration was 48 nmol/l. Less than 1% of women had a 25-hydroxyvitamin D concentration indicative of vitamin D deficiency (<17.5 nmol/l); whereas, over 60% of women had a 25-hydroxyvitamin D concentration indicative of insufficiency (<50 nmol/l). We estimate that 52 nmol/l was the threshold concentration for plasma 25-hydroxyvitamin D above which no further suppression of PTH occurred. Below and above this concentration the slopes of the regression lines were -0.18 (different from 0; P=0.003) and -0.01 (P=0.775), respectively. The relation between vitamin D status and parathyroid hormone concentration did not differ between women with low, medium or high calcium intakes (P=0.611); however, even in the highest tertile of calcium intake, mean calcium intake was only 657 mg/d.


CONCLUSIONS
On the basis of maximal suppression of PTH we estimate an optimal 25-hydroxyvitamin D concentration of approximately 50 nmol/l. Many women had a 25-hydroxyvitamin D below this concentration and may benefit from improved vitamin D status.
Green
T J
TJ
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Skeaff
C M
CM
Rockell
J E P
JE
Venn
B J
BJ
Lambert
A
A
Todd
J
J
Khor
G L
GL
Loh
S P
SP
Muslimatun
S
S
Agustina
R
R
Whiting
S J
SJ
D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007214:Indonesia; D008296:Malaysia; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000503:physiopathology*; D016387:Women's Health
D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D