9.3 – Vitamin deficiency

Related guidance:

Vitamin B12 deficiency in over 16s: diagnosis and management (NG239 March 2024)

• Visual summary on ongoing care and follow-up options for oral and intramuscular vitamin B12 replacement.

Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition Clinical guideline (CG32 February 2006, updated August 2017)

Alcohol-use disorders: diagnosis, assessment and management of harmful drinking (high-risk drinking) and alcohol dependence Clinical guideline (CG115 February 2011)

Alcohol-use disorders: diagnosis and management of physical complications Clinical guideline (CG100 June 2010, updated April 2017)

Non-alcoholic fatty liver disease (NAFLD): assessment and management NICE guideline (NG49 July 2016)

Vitamins for dietary supplementation (including vitamin B12 for vegans and vegetaerians) should be purchased over the counter as per self-care,  (except post bariatric surgery and renal dialysis).

• The entire population of the UK are at risk of having a low vitamin D status.
• Adults who are at higher risk of vitamin D deficiency include people aged 65 years and over who have low or no exposure to the sun, for example those who cover their skin; who are housebound or confined indoors for long periods, who have darker skin pigmentation, a malabsorption disorder, Coeliac disease, Cystic fibrosis, Crohn’s disease, following weight loss surgery, obesity, severe liver failure or end-stage chronic kidney disease, inherited enzyme disorders such as mutation of renal 25-hydroxyvitamin D 1 alpha-hydroxylase, taking certain drugs that reduce fat absorption (orlistat), antiepileptic drugs (especially carbamazepine, phenobarbital, and phenytoin), colestyramine, rifampicin, corticosteroids, thiazide diuretics, digoxin, calcium-channel blockers, antacids, highly active antiretroviral treatment (HAART) and are pregnant or breastfeeding. See NHS Somerset Vitamin D in pregnancy and breastfeeding.

• All adults should consider 400 IU (international units) (10 mcg) daily during autumn and winter and throughout the whole year if low or no exposure to the sun and minimal dietary intake. This includes those in institutions such as care homes, or who always cover their skin when outside, ethnic minority groups with dark skin, as may not get enough vitamin D from sunlight in the summer and who are pregnant or breast feeding. If you are unable to find a vitamin D supplement providing 10 micrograms (400 IU), products providing up to 25 micrograms (1000 IU) are suitable for everyone.
• Adults who are at higher risk of vitamin D deficiency may need to take a higher dose of vitamin D throughout the year. 800–2000 IU (20-50 mcg) daily and up to a maximum of 4000 IU (100mcg) daily for certain conditions such as malabsorption following specialist advice.
• Women and children who qualify for the Healthy Start scheme can get free supplements containing vitamin D. See NHS Somerset Infant Feeding for useful information and resources on Vitamin D and infant feeding.
• Normal usage of sunscreens does not generally prevent vitamin D synthesis.
• There is no evidence to support taking vitamin D supplements to specifically prevent or treat COVID-19.
• £136m could be saved by restricting prescribing for ‘minor’ conditions. Whilst Vitamin D maintenance therapy is recommended, there is no indication that this needs to be prescribed; vitamin D supplements can be bought cheaply and easily. Access to over the counter (OTC) medicines to self-care via Adult Social Care providers is an issue of equality. Policies should be in place to support people who wish to access OTC products in a timely manner.
• Routinely testing vitamin D levels in asymptomatic individuals is not recommended, based on a lack of evidence, except if osteomalacia is suspected and prior to osteoporosis treatment with a potent bone sparing agent (zoledronate, denosumab) or prior to Paget’s disease treatment with a bisphosphonate.
• Vitamin D supplementation alone or with calcium does not reduce fracture incidence among community-dwelling adults without known vitamin D deficiency, osteoporosis, or prior fracture.
• Vitamin D supplements only improve bone density and prevent fractures when marked deficiency is present and bone loss and fracture risk in older people are not related to calcium intake.
• NHS Somerset only recommend the use of Vitamin D₃ and Calcium supplementation alongside bone sparing treatment unless contraindicated. (with the exception of Bariatric patients as per SFT guidance). Calcium and vitamin D supplements may increase the risk of kidney stones. Calcium supplements can cause gastrointestinal upset, particularly constipation which can be a major issue in frail elderly people who are already prone to this problem. Frequency of acute admissions to hospital for abdominal problems doubled in those patients’ taking calcium. 
• See Disorders of bone metabolism for calcium and vitamin D formulations.
• Bisphosphonates remain first line treatment option for people with osteoporosis or high risk of fractures.
• NHS Somerset have approved the use of Bisphosphonates (off-label) to address significant unmet need for people with high risk of osteoporosis such as those with a diagnosis of osteopenia, who take aromatase inhibitors and long-term steroids (more than or equivalent to prednisolone 7.5 mg daily for 3 months or longer).
• Vitamin D₃ is recommended as the vitamin D preparation of choice for treatment of vitamin D deficiency. Growing research suggests that vitamin D₂ bioavailability may be significantly less when compared with vitamin D₃ although further research is required.
• Prescribe vitamin D₃ as a fixed loading dose if rapid correction is needed to treat deficiency. Arrange referral and seek specialist advice for patients that are predisposed to hypercalcaemia, sarcoidosis, tuberculosis, metastatic bone disease, some lymphomas, or primary hyperparathyroidism, malabsorption, previous/active renal stone disease, severe kidney, or liver disease or pregnant.
• The Vitamin D₃ loading regimen for treatment of deficiency should provide a total of approximately 300,000 IU of Vitamin D₃, given either as separate weekly or daily doses over 6–10 weeks.
• Routine intermittent administration of large doses of vitamin D ≥60,000 IU is not advised, based on reports of an associated increased risk of fracture and falls.
• Check the adjusted serum calcium level within 1 month after the last loading dose, or after starting lower dose maintenance treatment with vitamin D, to detect calcium deficiency or unmasked primary hyperparathyroidism. If hypercalcaemia is detected, advise to stop vitamin D (and calcium, if taking) supplements and arrange ongoing investigation and management.
• Prescribe cost effectively and by brand to ensure a licensed product or preparation suitable for specific needs is dispensed.

The British Dietetic Association (BDA) Vitamin D Food Fact Sheet

NICE and PHE Vitamin D thresholds and dose recommendations

Vitamin D₃ formulations

NHS Somerset Nutrition and Hydration