Diabetics are being warned that Apple's Health app is not compatible with some blood glucose measurements, meaning those in the UK and Australia could see inaccurate readings.
While Apple is releasing a software update to disable some elements of the app, this will be in advance of an expected fix for those who rely on the accuracy of the app's readings, such as diabetics.
Blood glucose monitoring is a vital part of managing diabetes and hypoglycaemia as it allows patients to monitor insulin levels and food intake to prevent potentially dangerous blood sugar fluctuations.
Apple's Health app allows users to manually enter and view blood glucose values, taken from an external device. However, these devices use different units of measurement to record blood sugar, depending on the region -- some countries, such as the United States, use mg/dL (milligrams per decilitre), while others such as the UK and Australia use mmol/L (millimoles per litre).
Although HealthKit supports both units of measurement, Apple's Health app only allows manual input and viewing of values in mg/dL, meaning UK and Australian users (and others) may face problems when it comes to inputting and viewing important blood sugar information.
"To prevent confusion in countries where mmol/L is commonly used, we'll soon release a software update that will temporarily remove the ability to manually enter and view blood glucose values in the Health app while we work on an update to support both units of measurement," the company wrote in an Apple Support post on its site.
"If you have previously entered values manually in the Health app, you'll no longer see this data in the Health app after the update. However, your data won't be deleted, and other apps with permission to read health data will still have access to blood glucose values that you previously entered."
Apple has advised that third-party apps will continue to be able to support both units of measurement, and will be able to continue using HealthKit APIs to store blood glucose data.
Launched at Apple's Worldwide Developers Conference in June, HealthKit is available with iOS 8 and is designed as a hub for health data, allowing users to track and monitor health-related information gathered through third-party devices.
Updated at 4:00 p.m. AEST to include Apple Support link.