1. Counsell, J.N. (1988) Vitamin fortification of foods. Fd Technol. Int. Europe, 211–8.
2. Department of Health (1991) Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report on Health and Social Subjects No. 41. HM Stationery Office, London.
3. Ghosh, H.P., Sarkar, P.K. and Guha, B.C. (1963) Distribution of the bound form of nicotinic acid in natural materials. J. Nutr., 79, 451–3.
4. Gregory, J.F. (1988a) Methodology for nutrient analysis. In Nutritional Evaluation of Food Processing (eds E. Karmas and R.S. Harris), Van Nostrand Reinhold Company Inc., New York, pp. 719–43.
5. Gregory, J.F. (1988b) Recent developments in methods for the assessment of vitamin bioavailability. Fd Technol, 42(10) 230, 233, 235, 237–8.