Vitamin D and Health

Summary & conclusions
9.59 The RNI for vitamin D recommended for the UK population is based on protection of musculoskeletal
health. The RNI represents the amount of a nutrient that is enough, or more than enough, to meet
the needs of 97.5% of the population.
9.60 A threshold serum 25(OH)D concentration of 25 nmol/L was used as the criterion for establishing the
RNI for vitamin D. This concentration represents a ‘population protective’ level; i.e., the concentration
below which risk of poor musculoskeletal health is increased and above which the risk is decreased at
a population level. The RNI was developed to ensure that the majority (97.5%) of the population has a
serum 25(OH)D concentration ≥ 25 nmol/L all year round.
9.61 Sunlight UVB exposure could not be taken into account in setting the RNI because it was not possible
to quantify the contribution it made to serum 25(OH)D concentrations within the general population.
9.62 The process of translating the target serum 25(OH)D concentration of ≥ 25 nmol/L into an RNI for
vitamin D was based on dose response RCTs carried out during winter when UVB radiation is absent or
minimal.
9.63 An RNI of 10 µg/d (400 IU/d) of vitamin D is recommended for the UK population aged 4y and above.
This represents the average amount of vitamin D (from natural food sources, fortified foods or
supplements) that is needed to achieve a serum 25(OH)D concentration ≥ 25 nmol/L during winter in
97.5% of the population. It refers to the average vitamin D intake over a period of time and takes
account of day to day variations in intake.
9.64 An RNI of 10 µg/d (400 IU/d) vitamin D for the general UK population aged 4y and over is a change to
current advice. 104
9.65 The RNI assumes minimal sunshine exposure.
9.66 As a precaution, it is recommended that the RNI is applicable throughout the year to protect
population groups and unidentified individuals in the UK with a serum 25(OH)D concentration
< 25 nmol/L in the summer.
9.67 The RNI of 10 µg/d (400 IU/d) recommended for the general UK population (4y and above) includes
pregnant and breast feeding women; i.e., a separate recommendation is now not required for
pregnant and lactating women. This is a change from previous advice.
9.68 The RNI of 10 µg/d (400 IU/d) makes provision for and therefore includes at risk population groups
(frail older adults and other individuals not spending substantial time outdoors, those wearing
concealing clothing; and people from ethnic groups with dark skin).
9.69 A Safe Intake range of 8.5-10 µg/d (340-400 IU/d) is proposed for infants aged 0-11m and includes
those who are exclusively breast-fed and those who are breast fed and part-formula fed, from birth.
The Safe Intake recommended for exclusively breastfed infants is a change to previous advice.
9.70 A Safe Intake of 10 µg/d (400 IU/d) is proposed for children aged 1 to < 4 y.
104 Current advice is that no dietary intake is necessary for individuals aged 4-64y with adequate exposure to sunlight.
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