To the Editor,
We comment on the recent reports on vitamin D deficiency in Oman both in pregnant women1 and those of childbearing age.2 Our objective is to share the utility of an enzyme-linked immunosorbent assay (ELISA) for an in-house assay of vitamin D3 levels that will eliminate any outside evaluation.1
Vitamin D3 deficiency is being evaluated at Sant Parmanand Hospital, a 140-bed, tertiary care, multidisciplinary private hospital in Delhi, India. With effect from April 2010, 25-hydroxy vitamin D [25(OH)D] levels are measured in the hospital laboratory using commercially available ELISA kits. We use the 25(OH)D direct Elisa Kit (Immundiagnostik AG, Bensheim, Germany), based on a competitive ELISA technique with a selected monoclonal antibody that recognises 25(OH)D. The results are expressed, after point-to-point calculation, as nmol/l (with 1 nmol/L being equivalent to 2.5 ng/mL). Values ≥80 nmol/L correspond to a sufficient level of vitamin D, while those of <50 nmol/L to a deficient, and 50–75 nmol/L to an insufficient level.
Among 20 pregnant women in delivery more than 75% were deficient in 25(OH)D. Vitamin D3 levels exceeded 75 nmol/l in three, while in two the respective values were between 50–74 nmol/l, and 15 had levels below 25 nmol/l.3
Future plans to address vitamin D deficiency in Oman1,2 should, in our opinion, include both vitamin D3 supplementation and a watch on post-supplementation vitamin D3 levels. A daily supplementation of 1000 IU of vitamin D3 may fail to bring levels to a minimum of 75 nmol/l in 20–30% cases.4
In view of the global prevalence of vitamin D deficiency among women of childbearing age,1,2,3 it would be desirable to initiate simple and rapid point-of-care assays for quantification of vitamin D3 levels in the general population, both in rural and urban areas.
References
- 1.Al Kalbani M, Elshafie O, Rawahi M, Al-Mamari A, Al-Zakwani A, Woodhouse N. Vitamin D status in pregnant Omanis: A disturbingly high proportion of patients with low vitamin D stores. Sultan Qaboos Univ Med J. 2011;11:52–5. [PMC free article] [PubMed] [Google Scholar]
- 2.Al-Kindi MK. Vitamin D Status in Healthy Omani Women of Childbearing Age: Study of female staff at the Royal Hospital, Muscat, Oman. Sultan Qaboos Univ Med J. 2011;11:56–61. [PMC free article] [PubMed] [Google Scholar]
- 3.Agarwal N, Arya SC. Vitamin D(3) levels in pregnant women and newborns at a private tertiary care hospital in Delhi, India. Int J Gynaecol Obstet. 2011;113:240–1. doi: 10.1016/j.ijgo.2011.01.005. [DOI] [PubMed] [Google Scholar]
- 4.Schwalfenberg GK. A step in the right direction. CMAJ. 2010;182:1763. doi: 10.1503/cmaj.110-2118. [DOI] [PMC free article] [PubMed] [Google Scholar]
