Vitamin D: advice for your patients
Vitamin D plays a vital role in helping to maintain health, but it can be difficult for the body to produce and absorb enough of it. This page contains resources explaining the importance of vitamin D, the causes of vitamin D deficiency and how it is tested, and advice you can give to patients.
Why is vitamin D important?
Vitamin D plays a crucial role in facilitating calcium absorption, which is needed for the body’s maintenance of healthy bones, muscles and teeth. It has also been found to be important in helping to protect muscle strength and prevent rickets, osteomalacia and falls.
Who is most at risk of vitamin D deficiency?
Babies and young children, pregnant and breastfeeding mothers, and people over the age of 65 are all at risk of vitamin D deficiency. Patients who spend very little time outside or those of darker skin tones living in northern climates may also be at risk.
What causes vitamin D deficiency?
Deficiency is seen in patients who do not consume enough vitamin D over time. This can be the result of a diet lacking in animal-based products, low exposure to natural sunlight, or high levels of melanin reducing the skin's ability to produce vitamin D.
Advice to give to patients to help prevent vitamin D deficiency
A healthy diet alone cannot ensure the correct levels of vitamin D, as few foods contain enough of it naturally. The latest advice recommends supplements should play a role in maintaining healthy levels of vitamin D. Read more guidance for patients.
Testing for vitamin D deficiency
The most common method of testing for vitamin D deficiency is through measuring levels of the vitamin in the blood. A typical test will measure the level of 25-hydroxy vitamin D per millilitre of sample taken.
Vitamin D seasonal deficiency
Between October and March, there is insufficient sunlight for the reliable dermal production of vitamin D. During winter in the UK, 30 to 40% of the general population across all age groups are classed as having vitamin D deficiency.1
Vitamin D in pregnant and breastfeeding women
The NHS recommends that pregnant and breastfeeding women should take at least 10mcg (400 IU) of vitamin D each day, while some in at-risk groups may need more2.
Who is at increased risk of vitamin D deficiency?
People aged 65+
Loss of bone density accelerates during the ageing process and the capacity for dermal synthesis required to produce vitamin D declines rapidly. Women are more at risk than men, due to the menopause, increasing the risk of conditions such as osteoporosis. A healthy, balanced diet, active lifestyle and vitamin D supplements are essential to maintaining healthy bones into old age.
Pregnant and breastfeeding women
Maternal vitamin D insufficiency is common during pregnancy and is associated with reduced bone-mineral accrual in the offspring during childhood; this association is mediated partly through the low levels of umbilical venous calcium.
A healthy, balanced diet, active lifestyle and vitamin D supplementation are essential to maintaining healthy bones into old age.
People with darker skin tones
People with naturally darker skin, from African, African-Caribbean and South Asian backgrounds are more at risk of vitamin D deficiency. This is because the pigment melanin is found in higher concentrations in darker skin. Melanin acts as a natural sunscreen and reduces the amount of UV radiation that is absorbed, meaning longer exposure to sunlight is required for vitamin D production.
People with covered skin
Those who cover their arms and legs, either with clothing for cultural reasons or with the heavy use of sunscreen for medical or cosmetic reasons such as skin cancer protection, medically diagnosed photo dermatosis or anti-aging wrinkle prevention, are more at risk of vitamin D deficiency. A sunscreen of SPF higher than 8 reduces the ability of the skin to make vitamin D by 99%.
Children under 5 years old
Children and young people in the following groups are at high risk of vitamin D deficiency. Primary prevention is therefore particularly important for:
• Children and young people with diets insufficient in calcium (e.g. vegan or low dairy intake) or with generally poor diets.
• Children and young people with limited sun exposure (e.g. veiled and photosensitive patients and patients who are advised to apply high factor sun block due to malignancy risk e.g. cancer survivors)
People who spend a lot of time indoors
Housebound people, those living in care homes or hospices, people who work long office hours, shift workers, and those suffering from conditions such as agoraphobia are among the groups of people who are at risk of vitamin D deficiency, due to reduced exposure to natural sunlight.