Orang Asli, the indigenous people of Peninsular Malaysia, is a minority population and placed behind in terms of socioeconomy, education and health. The Malaysian government has supported Orang Asli since the second Malaysia Plan in the 1970s, resulting in changes in their living standard, access to health, education and occupation. Hence, this review aims to assess the recent prevalence of diseases among Orang Asli in Peninsular Malaysia. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) review protocol guided this systematic review. The research question was formulated based on Population, Interest, Comparison and Outcome (PICO). The selected databases include Web of Science, Scopus, Ovid and EBSCOhost. The process of identification, screening and inclusion identified 33 articles. The mixed methods appraisal tool (MMAT) was then used to rank the quality of the articles. Selangor is the most frequent state involved in this review (12 studies), followed by Perak (10 studies), Pahang (10 studies) and Kedah (one study). We categorised into four categories of diseases, namely neglected tropical disease (n = 20), non-communicable disease (n = 6), nutritional status (n = 5), and hepatic disease (n = 2). The prevalence of diseases among Orang Asli is higher than in the general population, especially for soil-transmitted helminth (STH) and malnutrition. There is increasing research on non-communicable diseases due to an increasing trend in the socioeconomic status and lifestyle of the Orang Asli. Government agencies and private organisations must work together to empower Orang Asli with a healthy lifestyle, improve their socioeconomic status, and enhance food security, all of which will improve Orang Asli's health and reduce the prevalence of diseases.

Vitamin D is essential for maintaining serum calcium levels, ensuring sufficient bone mineralization, immunomodulatory properties, and a protective effect on the cardiovascular system, renal disease, cancer, as well as in pregnancy. Vitamin D deficiency is prevalent worldwide, and it is not related to a country’s development index. However, the data on vitamin D deficiencies are primarily taken from out-of-date, small-scale studies on target age groups or specific diseases, rather than from large-scale, population-based surveys. In Malaysia, for the past 16 years, studies were conducted involving adult men and women, pregnant women, postmenopausal women, adolescent, and children especially with specific diseases such as spina bifida, epilepsy, chronic liver disease, and atopic dermatitis. Only a few large surveys were conducted involving children and adolescents. Across the specific target population studied, vitamin D deficiency and insufficiency were seen particularly among females, Indians, and those of Malay ethnicity. This is related to widely known causes of vitamin D deficiency such as skin type (melanin) and sun avoidant lifestyles that include covering clothes, largely practiced by Malay Muslims in Malaysia. Other related causes or the high-risk groups are breastfed infants, the elderly, the obese, those on medications, and those characterized by fat malabsorption and geophysical factors. Vitamin D deficiency can be managed with pharmacological or non-pharmacological approaches, depending on the severity. The objective is to raise serum vitamin D to a normal level, hence, relieving the symptoms and reducing the adverse health outcomes. Despite no clear guidelines in treating vitamin D deficiency in Malaysia, this condition can be prevented with taking adequate vitamin D in food resources, sun exposure, or supplementation. Special attention should be given to high-risk groups including infants, obese patients, and the elderly.