diff --git a/example/src/App.tsx b/example/src/App.tsx
index 3c0a160..1722a07 100644
--- a/example/src/App.tsx
+++ b/example/src/App.tsx
@@ -3,6 +3,7 @@ import { read, useHealth } from '../../src/useHealth';
 import { useEffect, useState } from 'react';
 import { HealthLinkPermissions } from '../../src/types/permissions';
 import { HealthLinkDataType } from '../../src/types/dataTypes';
+import { BloodGlucoseUnit } from '../../src/types/units';
 
 export default function App() {
   const [bloodGlucose, setBloodGlucose] = useState<number | null>(null);
@@ -14,7 +15,7 @@ export default function App() {
       write: [HealthLinkPermissions.BloodGlucose],
     }).then(() => {
       read(HealthLinkDataType.BloodGlucose, {
-        unit: 'mg/dL',
+        unit: BloodGlucoseUnit.MmolPerL,
         startDate: new Date('2021-01-01').toISOString(),
       }).then((data) => {
         setBloodGlucose(data);
@@ -23,10 +24,7 @@ export default function App() {
   });
   return (
     <View style={styles.container}>
-      <Text>
-        Your blood glucose is{' '}
-        {bloodGlucose?.records[0].level.inMillimolesPerLiter}
-      </Text>
+      <Text>Your blood glucose is {bloodGlucose}</Text>
     </View>
   );
 }
diff --git a/src/types/units.ts b/src/types/units.ts
index 25db00b..5911413 100644
--- a/src/types/units.ts
+++ b/src/types/units.ts
@@ -1,4 +1,4 @@
 export enum BloodGlucoseUnit {
-  MgPerdL = 'mg/dL',
-  MmolPerL = 'mmol/L',
+  MgPerdL = 'mgPerdL',
+  MmolPerL = 'mmolPerL',
 }
diff --git a/src/useHealth.ts b/src/useHealth.ts
index d21de17..4866873 100644
--- a/src/useHealth.ts
+++ b/src/useHealth.ts
@@ -98,10 +98,10 @@ const readDataResultDeserializer = (
     return (data: any) => {
       switch (dataType) {
         case 'BloodGlucose':
-          if (options.unit === BloodGlucoseUnit.MmolPerL) {
-            return data[0]?.level?.inMillimolesPerLiter;
-          } else {
+          if (options.unit === BloodGlucoseUnit.MgPerdL) {
             return data[0]?.level?.inMilligramsPerDeciliter;
+          } else {
+            return data[0]?.level?.inMillimolesPerLiter;
           }
         case 'Height':
           return data[0]?.height?.inMeters;
@@ -112,21 +112,28 @@ const readDataResultDeserializer = (
   }
 };
 
+const iosCallback = (dataType: HealthLinkDataType, options: ReadOptions) => {
+  return new Promise((resolve, reject) => {
+    dataValueToIosReadFunction(dataType)(options, (err: any, results: any) => {
+      if (err) {
+        reject(err);
+      }
+      resolve(results);
+    });
+  });
+};
+
 export const read = async (
   dataType: HealthLinkDataType,
-  options: {
-    unit?: string;
-    startDate?: string;
-    endDate?: string;
-    ascending?: boolean;
-    limit?: number;
-  }
+  options: ReadOptions
 ) => {
+  let data;
   if (Platform.OS === 'ios') {
-    return dataValueToIosReadFunction(dataType)(options);
+    data = await iosCallback(dataType, options);
   } else if (Platform.OS === 'android') {
-    return readRecords(dataType, optionsToAndroidOptions(options));
+    data = readRecords(dataType, optionsToAndroidOptions(options));
   }
+  return readDataResultDeserializer(dataType, options)?.(data);
 };
 
 export const useHealth = () => {