Vitamin D insufficiency is high in Malaysia: A systematic review and meta-analysis of studies on vitamin D status in Malaysia

Abstract Vitamin D plays an important role in the immune system and many non-communicable diseases. The prevalence of vitamin D deficiency for the overall population of Malaysia is unknown. This study systematically reviewed and pooled studies that report vitamin D status from participants residing in Malaysia. PubMed, Scopus, Web of Science and MyJurnal were searched up to June 2021 without language restrictions. We include studies that reported the 25-hydroxyvitamin D (25(OH)D) concentrations and defined their cut-off for deficiency or insufficiency from healthy participants residing in Malaysia. Random effects model was used to pool vitamin D status using established cut-offs of < 30nmol/L, < 50nmol/L, and < 75nmol/L according to age group. We identified 203 studies, of which we included 31 studies in the meta-analysis. The pooled proportion for < 30nmol/L was 21% (95% CI 9–36, n = 2,438 from 10 studies), while the pooled proportion < 50nmol/L was 64% (95% CI 55–72, n = 13,927 from 29 studies), and < 75nmol/L was 85% (95% CI 61–100, n = 1,376 from 5 studies). Heterogeneity was high (I² ranged from 98–99%). Higher proportions of vitamin D insufficiency (defined as < 50nmol/L) were found in participants living in the urban areas (compared to rural areas), in females (compared to males), and in Malays and Malaysian Indians (compared to Malaysian Chinese) ethnicities. In conclusion, vitamin D insufficiency is highly prevalent in Malaysia, despite being a country that is close to the equator. We strongly urge prompt public health measures to improve the vitamin D status in Malaysia.