**5. Conclusion**

 Vitamin A is one of the fat-soluble vitamins that are vital for various biological roles in the human body, as it is essential for embryogenesis up to adulthood. It can be sourced from both animal-based (preformed vitamin A) and plant-based (provitamin A) foods. The evaluation of whether a population is vitamin A deficient or excess is determined by status monitoring. Biological and biochemical indicators are the most widely applied parameters in assessment of vitamin A status. Vitamin A deficiency or toxicity state arises under conditions where the dietary intake does not comply with recommended levels. It is crucial to note that both conditions could lead to various health complications with VAD leading to mainly xerophthalmia, increased infection risk and anaemia, while toxicity could result in chronic hypervitaminosis and hypercarotenemia. In line with this, prevention efforts that could improve vitamin A status are widely explored. Dietary diversification, fortification and supplementation are the three main approaches that are widely applied for this purpose. These continuous efforts are believed to be able in improving vitamin A status among the vitamin A-deficient populations.

## **Acknowledgements**

Utmost appreciation is conveyed to the Director General of Health Malaysia and the Director of Institute for Medical Research (IMR) for giving permission for this manuscript to be published as a book chapter. Special thanks to all staff of the Nutrition Unit, IMR, for their continuous support.
