Vitamin D and PBM in Kuwait Females

Summary

Vitamin D deficiency was thought to be an epidemic in regions depleted from sun shine during winter months. Extensive evidence shows that this is not totally the case, as vitamin D deficiency is equally reported from regions which enjoy sun shine during the whole year. Interestingly, the Middle East has reported notable numbers of hypovitaminosis D among the general population, but more commonly among females (Lips, 2007). Whereas increased published studies on vitamin D have been established in many parts of the Middle East, there has not been enough studies with regards to vitamin D in females in Kuwait.

Adolescent females face a higher demand given the critical period of growth with regards to bone mineral accrual. It is well proven that more than 90 % of the bone mass is laid during puberty and ceases when reaching the early twenties (Matkovic et al, 1994). Therefore, the adolescent years are increasingly important to obtain a high peak bone mass which may ultimately prevent/ delay osteoporosis.

Vitamin D is particularly necessary because it increases the intestinal absorption of dietary calcium which is necessary for the mineralization of the bone. Given its physiological role, vitamin D deficiency can cause a number of adverse health conditions such as rickets, ostomalacia, and on the long run, osteoporosis. Thus, an adequate vitamin D status in females would have the benefit of sustaining bone health, and assuring vitamin D adequacy for the foetus and breast-fed infants in case of pregnancy and lactation.

Project Status : November 2008

A total of 233 adolescent females (mean age 15.4 ± 1.67 y) were enrolled in the study and the data collection is now complete. Fasting blood samples were assayed for vitamin D status (ie, 25(OH)D), parathyroid hormone (PTH) and adjusted serum calcium. LS-BMC and LS-BMD (L1-L4) were measured using dual-energy x-ray absorptiometry (DXA) (Hologic, QDR 4500). Anthropometric measurements and skin-colour type were determined by standard methods. Food intake was assessed by a food frequency questionnaire. Duration of sunshine exposure, mode of dress and physical activity level were also obtained in standard questionnaires.

Khulood Alyahya has been successful in getting her PhD.

Project Objectives

The principal objectives are to:

Assess the level of vitamin D deficiency and insufficiency in Kuwaiti adolescent females aged 10-18 years old.

Assess the lifestyle habits of the Kuwaiti females and correlate these with their vitamin D and bone states.

Identify which adolescent females are at high risk for vitamin D deficiency by determining the main predictors of vitamin D deficiency, including habitual food intake and overall sun exposure.

Assess the seasonal variation in vitamin D status among the females, including the shift in UV-B and lifestyle.

Correlate the state of vitamin D with that of the bone by correlating PTH and calcium states.

Assess the vitamin D biochemical analysis performed in Al-Sabah hospital, as the only local laboratory to perform biochemical 25(OH)D testing, by comparing with standards (UK). This will determine the magnitude and direction of the quality and quantity of the local analysis.

No studies have yet to be completed on dietary acid load and bone health indices in the very elderly.

Results and Findings

A number of papers are now being prepared for peer review publication in key international journals aswell as abstracts for submittance to the 7th International Symposium on Nutritional Aspects of Osteoporosis, Lausanne and the 2009 Nutrition Society Summer Symposium, University of Surrey.

A number of key abstracts have been presented as follows:

Alyahya K. Almazeedi Z., Morgan JB., Berry J., Lanham-New SA. Extent of vitamin D deficiency in Kuwait adolescent females aged 10-18 years: implications for peak bone mass attainment. J Bone Miner Res 2006 Abstract.

Alyahya K., Almazeedi Z., Morgan JB., Berry J., Lanham-New SA., Lee WTK. Lifestyle habits of Kuwaiti adolescent females: a public health concern for optimisation of bone health. Proc Nutr Soc 2006 Abstract.