Vitamin D: policy context

The Scottish Government recommends supplementation for the following groups who are at risk of vitamin D deficiency:

Infants aged 6 months to 1 year (except if receiving >500mls of infant formula per day). 

8.5 to 10 µg per day

Children aged 1 to 4 years. 

10 µg per day

Housebound individuals, those resident within institutions, and those who habitually wear clothes that cover most of their skin whilst outdoors. 

10 µg per day

Those from minority ethnic groups with dark skin, pregnant women and lactating women

should consider taking 10 µg per day

This guidance is in line with the updated recommendations of the Scientific Advisory Committee on Nutrition (SACN). The advice for infants under 6 months will be published soon on the Scottish Government website. Free supplements are available for eligible women and children under the Healthy Start scheme.

At present, there is no agreed definition of vitamin D deficiency. Serum levels of less than 25 µg are generally regarded as deficient however other sources suggest that levels of over 50 µg are required for maintenance of bone health and that a level of 70-80 µg is optimum for general health. 

Although some observational evidence has suggested that lower levels of vitamin D may increase the risk of mortality and chronic diseases it is possible that this is mediated through the association of vitamin D deficiency with other risk factors, such as lack of physical activity and obesity, or because illness results in lower vitamin D levels. The effect of having higher than average vitamin D is also unclear, with one meta-analysis of observational studies suggesting that pancreatic cancer is more common in individuals with the highest levels. Some of the available observational evidence also suggests that all-cause mortality is higher in individuals with both the lowest and highest levels of vitamin D and that health benefits are greatest at more moderate concentrations. There have been few well-conducted randomised controlled trials of vitamin D supplementation in healthy adults and those that have been performed have not shown clear evidence of a benefit from taking supplements. The potential risks of excessive sun exposure must also be considered in the context of attempts to increase vitamin D levels. Clearer evidence is required regarding the health effects, safety and practicality of increasing population vitamin D levels and supplements cannot be recommended at present unless individuals are in a category known to be at high risk of deficiency.