Table 1.
Characteristics of the studies included in the final analysis.
| Study | Country | Study type | 25-hydroxyvitamin D cutoff point (ng/mL) | Patients exclusively with epilepsy/Total | Mean age (years) | Prevalence of 25-hydroxyvitamin D deficiency (%) | Minimum treatment time (months) | Antiepileptic drugs used |
|---|---|---|---|---|---|---|---|---|
| Marcus & Pettifor, 198018 | South Africa | Cross-sectional | ≤10 | 56/56 | 7.75 | 8.9 | 12 | Phenobarbital, phenytoin, primidone, carbamazepine, ethosuximide, diazepam |
| Farhat et al., 200219 | Lebanon | Cross-sectional | ≤10 | –/29 | 11.3 | 35 | 6 | Cytochrome P450 inducers and non-inducers (without specifying the medications used in the study) |
| Nicolaidou et al., 200620 | Greece | Cross-sectional | ≤10 | 51/51 | 7.4 | 37 | 12 | Cytochrome P450 inducers and non-inducers (without specifying the medications used in the study) |
| Nettekoven et al., 20082 | Germany | Cross-sectional | ≤20 | 38/38 | 8.4 | 76.3 | 3 | - |
| Krishnamoorthy et al., 200921 | India | Cohort | – | 25/25 | – | 0 | 3 | Carbamazepine, valproic acid |
| Rauchenzauner et al., 201022 | Austria | Cross-sectional | ≤10 | 125/125 | – | 0 | 6 | Valproic acid, sulthiame, oxcarbazepine, lamotrigine |
| Misra et al., 201023 | India | Cohort | ≤10 | 32/32 | 6.7 | 28 | 6 | Carbamazepine |
| Shellhaas et al., 201024 | USA | Cross-sectional | ≤20 | –/78 | 11.64 | 25 | – | Classified as “new” and “old” (without specifying the medications used in the study) |
| Borusiak et al., 201325 | Germany, Turkey, and Russia | Cross-sectional | ≤10 | 128/128 | 9 | 13.3 | 6 | Valproic acid, oxcarbazepine, lamotrigine, sulthiame, levetiracetam, carbamazepine, topiramate |
| Razazizan et al., 201310 | Iran | Cross-sectional | ≤15 | 48/48 | 7.1 | 0 | 6 | Phenobarbital, topiramate, carbamazepine, valproic acid |
| Turan et al., 20139 | Turkey | Cross-sectional | ≤20 | 144/144 | – | 52.7 | 6 | Valproic acid, carbamazepine, phenobarbital |
| Fong & Riney, 201426 | Australia | Cross-sectional | ≤20 | –/111 | – | 22 | 24 | Classified as “new” and “old” (without specifying the medications used in the study) |
| Ramelli et al., 201411 | Switzerland | Cross-sectional | ≤20 | 33/58 | 12.2 | 55 | 12 | Carbamazepine, oxcarbazepine, phenytoin, phenobarbital, clobazam, ethosuximide, lamotrigine, levetiracetam, stiripentol, sulthiame, topiramate, valproic acid, vigabatrin |
| Yaghini et al., 201513 | Iran | Cross-sectional | ≤10 | 90/90 | – | 53 | 6 | Carbamazepine, primidone, phenobarbital, valproic acid |
| Baek et al., 201427 | South Korea | Cross-sectional | ≤20 | 143/143 | 11.21 | 9.1 | 12 | Valproic acid, oxcarbazepine, lamotrigine, phenobarbital, levetiracetam, zonisamide, carbamazepine, topiramate |
| Lee et al., 201528 | South Korea | Cohort | ≤20 | –/143 | 7.4 | 61.5 | 12 | Cytochrome P450 inducers and non-inducers (without specifying the medications used in the study) |
| Vera et al., 201529 | Spain | Cross-sectional | - | –/33 | 6.5 | 0 | – | Valproic acid, carbamazepine, phenobarbital, lamotrigine, topiramate, phenytoin |
| Paticheep et al., 201530 | Thailand | Cross-sectional | – | –/30 | 9 | 23.3 | 6 | Phenobarbital, phenytoin, carbamazepine, oxcarbazepine, valproic acid, topiramate, levetiracetam, lamotrigine, benzodiazepine |
| Patil & Rai, 201531 | India | Cross-sectional | ≤20 | –/70 | – | 71.4 | – | – |
| He et al., 20165 | China | Cohort | ≤10 | 51/51 | 7.24 | 71 | 2 | Cytochrome P450 inducers and non-inducers (without specifying the medications used in the study) |
| Tosun et al., 201732 | Turkey | Cross-sectional | ≤12 | 54/92 | – | 31.5 | 24 | Valproic acid, topiramate, oxcarbazepine, carbamazepine, levetiracetam |
| Fong et al., 201612 | Malaysia | Cross-sectional | ≤14 | 244/244 | 12.3 | 22.5 | 12 | Cytochrome P450 inducers and non-inducers (without specifying the medications used in the study) |
| Yildiz et al., 201733 | Turkey | Cohort | ≤20 | –/172 | 9.6 | 54 | 12 | Valproic acid, carbamazepine, levetiracetam, phenobarbital |
| Chaudhuri et al., 201734 | India | Cross-sectional | ≤20 | 100/100 | 14 | 45 | 12 | Carbamazepine, clobazam, clonazepam, lamotrigine, phenobarbital, valproic acid, topiramate |
| Attilakos et al., 201835, 36 | Greece | Cohort | ≤20 | –/15 | 6.1 | 40 | 12 | Levetiracetam |
| Viraraghavan et al., 201937 | India | Cohort | ≤20 | –/29 | 7.1 | 62 | 6 | Phenytoin, valproic acid, carbamazepine |
| Sreedharan et al., 201838 | India | Cross-sectional | ≤12 | 56/56 | – | 16 | 6 | Carbamazepine andvalproic acid |
| Durá-Travé et al., 201839 | Spain | Cross-sectional | ≤20 | 90/90 | – | 27.2 | 12 | Valproic acid and levetiracetam |
| Fong et al., 201816 | Malaysia | Cross-sectional | ≤15 | –/87 | 11.9 | 21.8 | 12 | Valproic acid and cytochrome P450 inducers |