You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Application of ethnic food composition data for understanding the diet and nutrition of South Asians in the UK. Lack of food composition data, recipe information and portion sizes for ethnic foods are commonly reported problems for dietary assessment of ethnic minority groups. One of the main aims of this study was to use food composition data to validate portion sizes, identify important sources of nutrients and describe the characteristics of the South Asian diet. The top five ethnic foods containing highest levels of selected nutrients were lamb balti (3mg/100g iron), lamb kebab (3.2mg/100g zinc), mixed dhal (62μg/100g folate), fish curry (1.4μg/100g vitamin D), ghee (968μg/100g retinol) and toor dhal (9.1g/100g dietary fibre). Typical adult South Asian diets included traditional cereals (chapatti, rice and paratha) and low consumption of meat dishes; with vegetable curries contributing most towards energy intake. A higher consumption of full fat milk and fruit juices by toddlers and school children were observed when compared with the National Diet and Nutrition Survey of the UK.
{"Chemical": ["zinc", "iron", "retinol", "vitamin D", "folate"]}