TABLE 1.
Characteristics of studies included in the systematic review.
| References | State | Period data was collected | Total sample size (n), population | n, Ethnicity | Male (%) | Vitamin D measurement method | Number of participants, vitamin D classification [25 (OH)D concentrations are in nmol/L] |
| Rahman et al. (45) | Kuala Lumpur | Not reported | 274, postmenopausal women | 101, Malay 173, Chinese |
0 | Radio-immunoassay | 2, <25 deficient 93, 25–50 insufficient 179, 50–100 hypovitaminosis |
| Green et al. (46) | Kuala Lumpur | January and March 2005 | 378, non-pregnant women | 133 Malay 123 Chinese 122 Indian |
0 | Radio-immunoassay | 113, <17.5 deficient 227, <50 insufficient |
| Khor et al. (81) | Kuala Lumpur | 2008 | 402, from five primary school children | 51.2% Malay 42.8% Chinese 6% Indian and others |
44.8 | CLIA | 142, <37.5 deficient 149, <37.5–50 insufficient |
| Moy and Bulgiba (71) | Kuala Lumpur | May to July 2010 | 380, Malay employees | 100% Malay | 41.6 | CLIA | 258, <50 insufficient |
| Hawa et al. (82) | Kelantan | Not reported | 150, (51 pre-menopausal and 99 post-menopausal) | 100% Malay | 0 | ELISA | 1, <25 deficient 124, 25–49.8 insufficient 25, 50–100 hypovitaminosis |
| Nurbazlin et al. (83) | Kuala Lumpur and Negeri Sembilan | Aug 2010 to July 2011 | 400, women (293 urban, 107 rural) | 267, Malay 67, Chinese 66, Indian |
0 | ECLIA | 48, <30 deficient 74, 30–50 insufficient 278, ≥50 sufficient |
| Poh et al. (84) | Six regions in Malaysia (northern, central, southern, east coast, Sabah & Sarawak) | May 2010 to October 2011 | 2,936, children 4–12 years old | Not reported | 49.7 | CLIA | 1,395, <50 insufficient |
| Chin et al. (85) | Klang Valley | September 2009 to September 2011 | 383, men | Malay (39.2%), Chinese (60.8%) | 100 | ELISA | 2, <30 deficient 85, 30–50 insufficient |
| Jan Mohamed et al. (56) | Kelantan | April 2010 to December 2012 | 102, pregnant women | 100% Malay | 0 | HPLC | 4, <25 severe deficient 57, 25–50 mild deficient 35, 50–75 insufficient |
| Al-Sadat et al. (86) | Perak, Selangor and Kuala Lumpur | March 2012 to May 2012 | 1,361 school students | Malay 1091 (80.2) Chinese 105 (7.7) Indian 105 (7.7) Others 41 (3) |
38.6 | ECLIA | 20, <12.5 severe deficient 1,053, 12.5–37.5 deficient 187, 37.5–50 insufficient |
| Shafinaz and Moy (87) | Kuala Lumpur | February to May 2013 | 858 teachers from 30 schools | 76.9% Malay 16.4% Chinese 8.3% Indian 0.4% Others |
9.1 | ECLIA | 578, <50 deficient |
| Bukhary et al. (75) | Selangor | January to April 2014 | 396, pregnant women | 77.5% Malay 11.2% Chinese 8.8% Indian 2.5% Others |
0 | ECLIA | 174, <24.99 184, 25–49.99 deficient 33, 50–74.99 |
| Lee et al. (55) | Kuala Lumpur | August 2013 to August 2015 | 575 women completed 37 weeks of pregnancy (term) | 73.4% Malay 18.4% Chinese 4.9% Indian 3.3% others |
0 | UPLC | 412, <50 deficient 121, 50–75 insufficient |
| Moy et al. (88) | Kuala Lumpur | March to October 2013 | 770, female teachers | 76.6% Malay 15% Chinese 8.4% Indian |
0 | ECLIA | 557, <50 deficient |
| Rahmadhani et al. (70) | Kuala Lumpur | January 2012 to July 2012. | 941 boys and girls from 23 schools | 75% Malay 13% Chinese 10% Indian 2% Others |
28 | ECLIA | 305, <37.5 deficient 166, 37.5–50 insufficient |
| Ralph et al. (54) | Kota Kinabalu, Sabah | Ethics approved in 2010/1 | 92, controls for cases (tuberculosis) | Not reported | 35.8 | LCMS | 23, <50 deficient |
| Ariffin et al. (78) | Kuala Lumpur | March to August 2017 | 57, pregnant women | 86% Malay 14% non-Malay |
0 | ELISA | 15, <25 severe deficient 37, 25-49.9 mild deficient |
| Mat et al. (60) | Kuala Lumpur | November 2013 to October 2015 | 1,011, elderly | 31% Malay 36.3% Chinese 32.7 Indian |
43 | CLIA | 409, <50 deficient |
| Quah et al. (89) | Selangor, Perak and Kuala Lumpur | 1 April 2014 to 30 June 2014 | 1,016 students (14–15-year-olds) from 15 urban and rural schools | Not reported | 38 | CLIA | 338, ≤50 678, >50 |
| Jamil et al. (74) | Kuala Lumpur | March to July 2019 | 147, Malay office workers | 100% Malay | 0 | Enzymatic immunoassay | 133, <50 insufficient |
| Lee et al. (90) | Johor Bahru | 1st December 2016 and 31st May 2017 |
65, controls for cases (atopic dermatitis) | 67.7% Malay 16.9% Chinese 5% Indian 5% Others |
52.3 | ECLIA | 19, <50 deficient 22, 50–75 insufficient |
| Abd Aziz et al. (91) | Kuala Lumpur | Not stated, ethics approved in 2018 | 60, women | 87% Malay 7% Chinese 5% Indian |
0 | ELISA | 6, <30 deficiency 34, 30–50 insufficiency |
| Arumugam et al. (92) | Kuala Lumpur | June 2014 to February 2015 | 38, controls for cases (atopic dermatitis) | Not reported | 36.8 | ECLIA | 1, <30 deficient 22, 30–50 insufficient |
| Ismail et al. (93) | Kuala Lumpur | Not reported | 78, pregnant women | 77% Malay 15.4% Chinese 5.1% Indian 2.5% Others |
0 | ECLIA | 27, <30 deficient 36, 30–50 inadequate |
| Leiu et al. (94) | Kuala Lumpur and Selangor. | Not reported | 214, post-menopausal Chinese women | 100% Chinese | 0 | CLIA | 71, <30 deficient 106, 30–50 insufficient |
| Ismail et al. (95) | Kelantan | August 2017 to October 2017 | 126, healthy volunteers | 100% Malay | 43.7 | CLIA | 92, <30 deficient 12, 30–50 insufficient |
| Woon et al. (58) | Kuala Lumpur and Selangor | November 2016 and January 2018 | 535, late pregnancy | Not reported | 0 | CLIA | 227, <30 deficient |
| Aris et al. (26) | Kelantan | May to June 2012 | 119, indoor workers, 119, outdoor workers | 100% Malay | 31 (indoor) 93.3 (outdoor) |
ECLIA | 64, <50 deficient 46, 50–75 insufficient |
| Hussain and Elnajeh (59) | Kelantan | Not stated, ethics approved in 2012 | 361, adolescents from 10, schools | 85% Malay 15% Chinese |
37.1 | ECLIA | 59, <30 deficiency |
| Chee et al. (96) | Kuala Lumpur | August 2017 to August 2019 | 243, 9- to 11-year-olds | 90.5% Malay 9.5% Indian |
52.3 | LC–MS/MS | 46, <30 deficient 123, <50 inadequate |
| Mustapa Kamal Basha et al. (57) | Kuala Lumpur | November 2017 to March 2019 | 179, longitudinal study of pregnant women | 78% Malay 13.6% Chinese 6.8% Indian 1.7% others |
0 | HPLC | 161, <50 deficient |
| Razip et al. (97) | Selangor | Not reported | 50, controls for adult diabetes patients aged 30 to 65 | 90% Malay 2% Chinese 8% Indian |
56 | HPLC | 41, <50 deficient 8, 50–200 Optimal 1, >200 Toxic |
HPLC, high-performance liquid chromatography; LC-MS/MS, liquid chromatography with tandem mass spectrometry; ECLIA, electrochemiluminescence immunoassay; ELISA, enzyme-linked immunosorbent assay; CLIA, chemiluminescent immunoassay.