Only small amounts of vitamin D come from dietary sources as it is mainly synthesised in the skin from the ultraviolet B (UVB) fraction of sunlight if the person is sufficiently exposed to direct sunlight. Vitamin D deficiency has been well documented in Oman. The "2004 Oman National Micronutrients Survey" and other recent studies revealed that vitamin D3 stores are low among healthy Omani females of childbearing age and pregnant women. This situation is confusing as Oman is known to be one of the sunniest countries in the world. However, it is known that most Omani women are well covered and for various reasons avoid sun exposure. The article addresses a question about the balance that should be maintained between excessive sun exposure that leads to an increased risk of skin cancer, and healthy exposure that provides sufficient ultraviolet radiation (UVR) to maintain adequate vitamin D levels. In order to avoid vitamin D deficiency, sun exposure or protection messages must be tailored according to different situations, in recognition of the complex combination of personal, cultural and social factors that affect vitamin D synthesis in the skin.