West and North London (WNL) has published updated vitamin D monitoring guidance for the boroughs of Barnet, Camden, Enfield, Haringey and Islington. Developed in partnership with the Royal College of Pathologists, the guidance supports more appropriate vitamin D testing and monitoring across primary and secondary care, helping to reduce unnecessary testing while ensuring patients receive the right care at the right time. 

Key points for general practice

• Only request vitamin D testing where there is a clear clinical indication, such as suspected osteoporosis, osteomalacia, malabsorption syndromes, hyperparathyroidism, or specific paediatric indications. 
• Do not request vitamin D levels in isolation. A bone profile should also be considered, as it is a better marker of calcium homeostasis. 
• Routine repeat testing is not recommended for asymptomatic patients responding to treatment. 
• Vitamin D levels should not normally be rechecked within three months of starting replacement therapy
• Only re-test if it will change clinical management. 

To support implementation, GP order communications systems will introduce alerts for repeat vitamin D requests made within 90 days of a previous test. This will help reduce unnecessary repeat testing and promote consistent practice across north central London. 

For further information, review the full WNL Vitamin D Monitoring Guidance, which includes detailed testing indications, monitoring advice and referral recommendations.