There is no agreement about normal level of vitamin D and its deficiency
stages. For finding normative value of Vitamin D and evaluating the state
of vitamin D level in Iranian population we revised the data that was
collected in Iranian national Multi-center Osteoporosis Study (IMOS).
We chose 5 cities with different climates; individuals were selected by
random cluster sampling. Healthy people aged 20-69 were entered into the
study and serum vitamin D and PTH levels were measured. We stratified
subjects based on their vitamin D levels in 7 groups and compared mean
PTH levels of adjacent groups. We evaluated 5329 blood samples for vitamin
D and PTH and found three steps of PTH elevation with decreasing vitamin
D levels for women (40, 25 and 12 nmol L-1) and two (35 and
25 nmol L-1) for men. We use these values as cutoff levels
for definition of normal, mild, moderate and severe vitamin D deficiency
states. Based on these cutoffs, prevalence of all stages of vitamin D
deficiency was unexpectedly high in all cities. Vitamin D deficiency state
was seen in 75.1% of women and 72.1% of men. The high prevalence of vitamin
D deficiency in Iran is similar to the results of other studies in Middle
East area and indicates a need for a careful search for a determination
of cause and need for regular fortification program.
K. Moradzadeh, B. Larijani, A.A. Keshtkar, A. Hossein-Nezhad, R. Rajabian, I. Nabipour, G.H. Omrani, A. Bahrami, M.M. Gooya and A. Delavari, 2008. Normative Values of Vitamin D Among Iranian Population: A Population
Based Study. International Journal of Osteoporosis and Metabolic Disorders, 1: 8-15.