Vitamin amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B (thiamine), vitamin B (riboflavin), vitamin B (niacin), vitamin B (pantothenic acid), vitamin B (pyridoxine), vitamin B (biotin), vitamin B (folic acid or folate), vitamin B (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones). Vitamins have diverse biochemical functions. Some forms of vitamin A function as regulators of cell and tissue
B2 First certificate also contains the UK National Qualifications Framework (NQF) level. The candidate’s overall score is averaged from the individual scores for each skill (Reading, Writing, Listening and Speaking) and for the use of English. B2 First is targeted at CEFR Level B2, but also provides reliable assessment at the level above B2 (Level C1) and the level below (B1). The following scores are used to report results: Scores between 122 and 139 are also reported on the Statement of Results but candidates will not receive a certificate. Pre-2015, the Statement of Results had the following information, reflecting the total combined