Manufacturing Standards


Desunin is manufactured according to Good Manufacturing Practice and Good Distribution Practice.

Good manufacturing practice (GMP)1 is the minimum standard that a medicines manufacturer must meet in their production processes. Products must: 

  • be of consistent high quality
  • be appropriate to their intended use
  • meet the requirements of the marketing authorisation (MA) or product specification

Good distribution practice (GDP)1 requires that medicines are obtained from the licensed supply chain and are consistently stored, transported and handled under suitable conditions, as required by the Marketing Authorisation Holder or product specification.
Organisations that may have to comply with good manufacturing practice (GMP) and/or good distribution practice (GDP) include:

  • manufacturer licence holders
  • wholesale dealer licence holders
  • blood establishment authorisation holders
  • non-UK sites employed by UK MA holders

MHRA carries out inspections to check if manufacturing and distribution sites comply with GMP or GDP, including overseas manufacturing sites.


The requirements for producing unlicensed vitamin D are less stringent.
Recent studies2 reveal a wide variation in the actual vitamin D content of products, particularly unlicensed formulations versus the stated dose.
One investigation2 revealed 6/14 unlicensed products were not within 10 % of the stated dose but had a range of 8% to 201% of the dose claimed2.
Another demonstrated only 5/15 preparations were within 10 per cent of the stated dose2.
Of these, the licensed products revealed the greatest accuracy with least variation compared with the stated dose2.
As well as being more expensive, these products also have the potential to expose patients to risk.
Accordingly, the best way forward is to use licensed vitamin D3 products authorised by the UK Medicines Healthcare Products Regulatory Authority (MHRA) for efficacy, safety and quality.2 Typically, these are available by prescription, rather than supermarket or OTC purchase.


  1. Good Manufacturing Practice and Good Distribution Practice. Available at
  2. Vinay Eligar, J Stephen Davies. Prescriber December 2014, pg 7-8. Available at