§ The Countess of Marasked Her Majesty's Government:
What studies have been conducted on individuals taking vitamin B6, or responding to it, to establish the need for supplementation of their normal diet.
§ Baroness Jay of PaddingtonThe Government take expert medical advice on the level of nutrients required by the population from the Committee on Medical Aspects of Food and Nutrition Policy (COMA). COMA' s report"Dietary Reference Values for Food Energy and Nutrients for the United Kingdom" published in 1991 details the studies which led to the recommendations. A copy of the report is available in the Library.
§ The Countess of Marasked Her Majesty's Government:
Whether they are aware that there are individuals who have difficulty either in absorbing vitamin B6 or in utilising it because of the presence of a competing aldehyde, and whether there is any evidence that a deficit of vitamin B6 may cause sensory neuropathy.
§ Baroness Jay of PaddingtonThe Government are aware that there are circumstances, defined in the British National Formulary, in which individuals with metabolic deficiencies require dosage with vitamin B6. A peripheral neuritis may occur in cases of vitamin B6 deficiency.
§ The Countess of Marasked Her Majesty's Government:
What clinical studies have been conducted on the levels of vitamin B6 in the population of the United Kingdom to support the statement by the Parliamentary Under-Secretary, the Welsh Office (letter to Dr. Alan Williams, MP, 29 September 1997) that "deficiency is rare".
§ Baroness Jay of PaddingtonStudies of the intake of vitamin B6 have been undertaken as part of the254WA Dietary and Nutritional Survey of British Adults, which was published in 1990 and is available in the Library. The report demonstrates that very few persons would have intakes lower than the lower reference nutrient intake (LRNI) for vitamin B6.
§ The Countess of Marasked Her Majesty's Government:
Whether they will place in the Library of the House a list of the "over 100 scientific papers published in national and international journals", reviewed by the Committee on Toxicity of Chemicals in Food as a basis for their recommendation that the sale of non-prescription vitamin B6 should be restricted to doses of a maximum of 10mg (Letter from the Parliamentary Under-Secretary, the Welsh Office to Dr. Alan Williams, MP, 5 September 1997); and whether they will indicate which of those papers demonstrated toxic reactions which occurred as a result of excessive doses of vitamin B6.
§ Baroness Jay of PaddingtonThe Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) made their recommendations after considering the totality of the published literature on vitamin B6 toxicity and submissions from industry and other interested parties on vitamin B6. Lists of the scientific papers considered by the COT have already been placed in the Library. The COT statement, published on 4 July, included examples of papers which demonstrated toxic reactions to excessive doses of vitamin B6. A copy of the statement is also available in the Library.
§ The Countess of Marasked Her Majesty's Government:
Whether they consider that the results of the study by Berger, Schaumberg et al Dose response, coasting and differential fiber vulnerability in human toxic neuropathy: A prospective study of pyridoxine neurotoxicity (July 1992 Neurology 42 1367), would justify further research on a larger population.
§ Baroness Jay of PaddingtonThe paper by Berger, Schaumburg, Schroeder, Apfel and Reynolds (1992,Neurology, 42, 1367–1370) was one of those considered by the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment in its review of vitamin B6 toxicity. The authors' conclusions that the results confirm earlier experimental and clinical reports that vitamin B6 produces a peripheral neuropathy contributed to the development of the committee's view. The study used a valuable combination of objective measures and subjective observations but it would be difficult to apply these to larger populations.