Vitamin D Deficiency in Adults

Transcription

1 Vitamin D Deficiency in Adults Around 50% of the UK adult population have vitamin D insufficiency in winter and spring, whilst the prevalence of vitamin D deficiency is 16%. 1 This means that in Wandsworth alone there may be around 116,500 adults with vitamin D insufficiency at that time of year with over 37,000 of these who will be deficient. Vitamin D is essential for good bone health and more recently insufficiency has been linked to other health concerns. 2 *menclature: The term vitamin D is used for a range of compounds. Vitamin D2 is known as ergocalciferol. Vitamin D3 is known as cholecalciferol when referring to the analyte and colecalciferol (the recommended International nproprietary Name (rinn)) when referring to the drug.* What are the sources of vitamin D? The main source of vitamin D for humans is ultraviolet B sunlight exposure. During summer two or three exposures (of at least the face and arms without sunscreen and not behind glass) of 20 to 30 minutes each week, which can be divided, between 10am and 3pm should provide adequate amounts of vitamin D for most individuals. 2 The elderly and those of non white ethnicity will have higher requirements. Due to the latitude in the UK, from October to April sun exposure is not adequate for synthesis of vitamin D. Oily fish such as herring, sardines, mackerel, salmon and tuna are the best dietary source of vitamin D. Egg yolks, mushrooms and liver contain small amounts of vitamin D. Liver is also a rich source of vitamin A, therefore consumption should be limited to once a week to avoid toxicity and avoided entirely in pregnancy. There are also some foods such as margarines, cereals that are fortified with vitamin D (check product labels). 2,3,4 What is the recommended daily intake of vitamin D? In the UK, a recommended dietary intake (RDI) has not been set for those leading a normal lifestyle where they are exposed to solar radiation. For adults over 65 years or at risk (e.g. confined indoors, extensively covered), and for pregnant or breastfeeding women the reference nutrient intake (RNI) is 400units (10mcg) per day 5. The latter recommendation during pregnancy is endorsed by the Department of Health (DoH). *1mcg is equivalent to 40units. Units will be used throughout this document* Based on current evidence however the consensus is that current governmental guidelines in all countries are too low with respect to how much daily vitamin D is required to maintain bone health and health in general, particularly in the absence of adequate sun exposure. 2,3,4 How is vitamin D insufficiency and deficiency determined? The most reliable way to determine vitamin D deficiency is by assay of serum 25 hydroxyvitamin D (25(OH)D) either by measuring 25 hydroxy vitamin D3 or total 25 hydroxy D2 and D3. 25(OH)D3 is a metabolite of cholecalciferol (vitamin D3), as opposed to a metabolite of ergocalciferol (vitamin D2) or total vitamin D. Either assay may used at local institutions. It is important to establish the assay used at the laboratory where the requests are sent as this has implications assessing treatment response. Prepared April 2010, updated August 2010, approved St George s Hospital DTC and NHS Wandsworth CEMMaG October 2010 Sharon Wouda, GP Prescribing Advice Pharmacist, NHS Wandsworth On behalf of a vitamin D working group between St George s Hospital and NHS Wandsworth 1

2 There is some consensus that vitamin D deficiency should be defined as 25(OH)D concentration of less than 25 nmol/litre. 2,4 This is the level below which parathyroid hormone (PTH) starts to rise causing increased bone turnover and hence the symptoms associated with osteomalacia. Serum 25(OH)D concentration Vitamin D status Manifestation Management <25 nmol/l Deficient Rickets Osteomalacia nmol/l Insufficient Associated with disease risk Treat with high dose vitamin D Vitamin D supplementation nmol/l Adequate Healthy Lifestyle advice >75 nmol/l Optimal Healthy ne When should vitamin D levels be measured? Routine testing of vitamin D levels is not recommended given the large proportion of the population who may have insufficient levels. Vitamin D deficiency should be considered and checked for only if: 1. A patient has one or more of the following clinical features: 2,5,6 Insidious onset of widespread or localised bone pain and tenderness (especially lower back and hip pain, but may include rib, thigh or foot pain) Proximal muscle weakness i.e. in quadriceps and glutei. This may cause difficulty rising from a chair and/ or a waddling gait Swelling, tenderness and redness at pseudo fracture sites Fractures, typically femoral neck, scapula, pubic rami, ribs or vertebrae n specific myalgia especially with a raised creatine kinase (CK) Myalgia on prescription of a statin AND 2. The patient has one or more of the following risk factors: 2,5,6 Black and ethnic minority patients with darker skin Elderly patients in residential care or housebound Intestinal malabsorption, for example coeliac disease, crohn s disease, gastrectomy Routine covering of face or body, for example wearing a veil or habitual sunscreen use Vegan or vegetarian diet Liver or renal disease Medications including anticonvulsants, cholestyramine, rifampicin, glucocorticoids, antiretrovirals AND 3. Other causes for symptoms have been excluded, for example myeloma, rheumatoid arthritis, polymyalgia rheumatica and hypothyroidism. 2

3 It is worthwhile encouraging all patients with risk factors even those not exhibiting symptoms to make lifestyle changes in order to achieve adequate amounts of vitamin D but it is not necessary to measure their levels. Pregnancy and breastfeeding are also risk factors for vitamin D deficiency however these two groups are outside the scope of this document. Refer to relevant NICE and Royal College of Obstetricians and Gynaecology guidelines, and the DoH Healthy Start Program. How should vitamin D status be assessed? Assessment of vitamin D status should include 25(OH)D, serum calcium (to exclude hypercalcaemia and provide a baseline for monitoring), parathyroid hormone (PTH) (to exclude primary hyperparathyroidism), alkaline phosphatase (ALP) and phosphate. Renal function (to exclude renal failure), liver function tests (to exclude hepatic failure), and full blood count (anaemia may be present if there is malabsorption) are also recommended. The blood test for PTH is unstable therefore phlebotomy needs to take place at the site where the assay is processed. How should vitamin D deficiency be treated? Colecalciferol (vitamin D3) is considered the preferred form of vitamin D for treatment. It has been reported that colecalciferol raises vitamin D levels more effectively than ergocalciferol (vitamin D2), and has a longer duration of action. 7,8 This may be due to higher affinities of colecalciferol and its metabolites for liver enzymes, plasma vitamin D binding protein, and vitamin D receptors. 9 Whilst ergocalciferol is effective in treating vitamin D deficiency, the differences in potency suggest that where possible colecalciferol should be used. Furthermore, considering some assays used in the local area may only measure a metabolite of colecalciferol response to treatment may not be detected if ergocalciferol is given. Deficiency (25(OH)D less than 25nmol/L) will require high dose colecalciferol; First line: 60,000units (3 x 20,000unit capsule) colecalciferol orally once a week for 12 weeks. Second line: two intramuscular (IM) injections of 300,000units colecalciferol given 3 months apart (use this option if malabsorption present or compliance is problematic). Third line: 150,000units (50mL of 3,000units/mL liquid or equivalent) colecalciferol once a day for 2 days (use oral liquid option only if capsules or injection are not suitable). Insufficiency (25(OH)D 25 to 50nmol/L) should be treated with oral supplementation of 1,000 to 2,000units of colecalciferol taken daily for 12 weeks. Maintenance therapy at a dose of 800 to 1,000units of colecalciferol daily may be required once deficiency has been corrected for those patients who were severely deficient and are still considered to be at risk. In some cases this may be lifelong therapy. First line: one tablet twice a day of a calcium carbonate 1.5g & colecalciferol 400units (10mcg) combined preparation (essential for all institutionalised patients over 65 years). Second line: 1,000units colecalciferol taken orally once a day (only if patients have adequate dietary calcium intake or are at risk of hypercalcaemia). 3

4 As a fat soluble vitamin oral vitamin D products should be taken with food to improve absorption. Avoid taking with orlistat as this reduces absorption. Whilst on treatment patients should be advised of signs of hypercalcaemia; nausea, thirst and polyuria. 4 Which vitamin D products are recommended? The only licensed preparations of vitamin D alone in the UK contain ergocalciferol (vitamin D2); 10,000unit and 50,000unit tablet, and 300,000unit and 600,000unit injection. However as mentioned above colecalciferol (vitamin D3) is the preferred treatment. Furthermore there have been ongoing supply issues with ergocalciferol. Although there are no UK licensed medicinal products containing only colecalciferol available to prescribe on the NHS, options are outlined below to meet the recommended treatment. Despite some of the recommended options being unlicensed, clinical responsibility always lies with the prescriber. High dose colecalciferol (vitamin D3) These will be required for deficiency and are only available on prescription. A colecalciferol 20,000unit capsule (Dekristol; MIBE, Germany) is licensed in Europe. This is the most appropriate option to provide 60,000units once a week orally for patients with deficiency. Caution in patients with allergies and dietary restrictions as this product contains peanut oil, glycerol, gelatin and soya. OR Where intramuscular administration is required, a colecalciferol 300,000unit injection (Vitamin D3; Streuli, Switzerland) is licensed in Europe. These preparations can be obtained through a company in the UK with a license to import, such as IDIS ( ), Martindale Pharma ( ), Mawdsley Unlicensed (via Specials Laboratory or Quantum Specials ), and Durbin ( ). Most pharmacies or pharmacy wholesalers will have an account with one of these companies. Ordering directly from the importer is usually the most cost effective route of procurement with quotes obtained indicating a cost of approximately 30 for a box of 50 capsules. Colecalciferol preparations of various strengths are manufactured by commercial or hospital MHRA licensed manufacturing units. Specials products such as these are not commercially available and need to be extemporaneously prepared. This can be costly as there is no price regulation. These liquid preparations usually have a short shelf life therefore do not prescribe quantities of more than one month s supply without confirming a longer expiry. It is usually more cost effective to order directly from the manufacturer, for example colecalciferol 300,000unit in 100mL liquid (30 day expiry after opening) from Martindale Pharma ( ) costs 72 or colecalciferol 300,000units in 10ml solution (SGH formula, 7 day expiry) from St George s Hospital ( ) costs 65. Low strength colecalciferol (vitamin D3) These products can be used for insufficiency or maintenance. 4

5 Colecalciferol health food supplements (not licensed medicines) are available to prescribe or purchase over the counter (OTC) from retail pharmacies and health food stores. For patients not exempt from prescription charges these supplements are less expensive to purchase OTC than to obtain on prescription. Where possible purchasing OTC should be encouraged. If purchasing OTC is not an option, colecalciferol 1,000unit tablet or capsule should be prescribed. This prescription can be dispensed either with an OTC supplement or a 1,000unit tablet licensed in Europe (Vigantolettin; Merck Pharma, Germany). Examples of colecalciferol supplements; Product Strength and form Source Relevant excipients for any dietary/allergy restrictions* Sunvite Vitamin D3 400unit and 1000unit tablet Holland and Barrett Soya, gelatin (bovine origin) Vitamin D 500unit capsule Boots Soya bean oil, gelatin, glycerin Vitamin D 1000unit capsule Nature s Remedy Rice bran oil, gelatin, glycerin Vitamin D 1000unit tablet Nature s Remedy Nil suitable for vegetarians BioLife Vitamin D 1000unit tablet Lifestyle Natural Health Nil suitable for vegetarians Vitamin D3 1000unit softgel Solgar Gelatin, glycerin *Colecalciferol in supplements is derived from wool oil (lanolin); Products with soya are not suitable for those with nut allergies Combined calcium and vitamin D preparations are licensed in the UK and available to prescribe on the NHS. They are mostly commonly available with 5mcg or 10mcg (200 or 400units) of vitamin D in the form of colecalciferol (vitamin D3) together with 1.25g or 1.5g of calcium carbonate. As UK licensed products, these are the most appropriate option to use for maintenance depending on a patient s calcium level and dietary intake of calcium. When is vitamin D supplementation not suitable? Vitamin D is contraindicated in patients with hypercalcaemia or metastatic calcification. 4 Relative contraindications include primary hyperparathyroidism, renal stones and severe hypercalciuria. 4 What monitoring should be done? In vitamin D deficiency 25(OH)D should be re checked 12 weeks after commencing high dose replacement treatment in order to monitor response. It is not necessary to monitor 25(OH)D in vitamin D insufficiency where low dose treatment is given. In patients with renal failure, serum calcium should be checked regularly for a few weeks after starting treatment. Once vitamin D deficiency is corrected monitoring every 12 months may be advisable for patients still considered at risk. Who should be referred to secondary care? Patient with the above contra indications Patients with renal impairment (stage 4 Chronic Kidney Disease (CKD) or egfr less than 30ml/minute) Primary hyperparathyroidism response after 12 weeks of treatment 5

6 Cost implications It is estimated that at present 21,564 vitamin D assays are completed at St George s Hospital per year. If cases of vitamin D insufficiency and deficiency identified were treated according to these guidelines the total cost would be 540,615. If we assume that 60% of all assays were done on Wandsworth patients this estimates to 324,369. However, the prevalence of vitamin D insufficiency and deficiency is much greater than the number currently identified. If all cases in Wandsworth were correctly identified and treated the estimated cost would be 2,963,520. Comparison of costs in Wandsworth between cases vitamin D deficiency and insufficiency currently tested and treated against estimated costs if all cases were identified Number in Wandsworth Estimated current cost/ year Projected cost if all cases identified Men (18+ years) 113,893 Vitamin D insufficiency (34%) 38,724 Vitamin D deficiency (16%) 18,223 Women (18+ years) 121,214 Vitamin D insufficiency (34%) 41,213 Vitamin D deficiency (16%) 19,394 Total (18+ years) 235,107 Vitamin D insufficiency (34%) 79,936 72,493* 1,247,805* Vitamin D deficiency (16%) 37, ,876** 1,715,715** *Based on per Vitamin D assay. Assumes over the counter preparations used to treat Vitamin D insufficiency **Based on per Vitamin D assay + estimated 30 per 12 week course high dose vitamin D Based on tests completed at St George s Hospital between April May 2010, extrapolated to 12 months and assumption that Wandsworth represents 60% of total assays done Based on estimated prevalence of vitamin D deficiency and insufficiency in Wandsworth References: 1. Hypponen E, Power C. Hypovitaminosis D in British adults at age 45 y:nationwide cohort study of dietary and lifestyle predictors. Am J Clin Nutr. 2007;85: Pearce SHS, Cheetham TD. Diagnosis and management of vitamin D. BMJ 2010; 340: rman AW, et al. The Workshop consensus for vitamin D nutritional guidelines. J Steroid Biochem Mol Biol 2007; 103: Primary vitamin D deficiency in adults. DTB 2006; 44: DoH. Dietary reference values for food energy and nutrients for the United Kingdom: report of the panel on dietary reference values of the committee on medical aspects of food policy. Report on health and social subjects 41. London: HMSO, Holick MF. Vitamin D deficiency. NEJM 2007; 357: Trang HM, et al. Evidence that vitamin D 3 increases serum 25 hydroxyvitamin D more efficiently than does vitamin D 2. Am J Clin Nutr 1998; 68: Armas LAG, et al. Vitamin D 2 is much less effective than vitamin D 3 in humans. J Clin Endocrinol Metab 2004; 89: Houghton LA, Vieth R. The case against ergocalciferol (vitamin D 2 ) as a vitamin supplement. Am J Clin Nutr 2006; 84:

7 Investigation and treatment of Vitamin D deficiency Does the patient have 1 symptom of vitamin D deficiency? widespread bone pain or tenderness or myalgia proximal muscle weakness tenderness over pseudofractures Insufficiency fractures Vitamin D testing not required Does the patient have 1 risk factor for vitamin D deficiency? black or ethnic minority elderly and housebound habitual skin covering vegan/vegetarian liver/renal disease malabsorption anticonvulsants, cholestyramine, rifampicin or anti retrovirals Have other causes for symptoms been excluded? Assessment of vitamin D status required: 25(OH)D, Ca 2+, PTH, ALP, PO 4. Also recommended: U+Es, LFTs, FBC Vitamin D testing not required at present. First exclude other causes for symptoms. Do any of the following apply? Hypercalcaemia Metastatic calcification Renal stones Severe hypercalciuria Stage 4 CKD or egfr < 30ml/minute Primary hyperparathyroidism Refer to appropriate specialist in secondary care. Depending on outcome vitamin D treatment may still be required; of which the first treatment course should be prescribed and provided by secondary care before transferring patient with care plan back to primary care. Treatment based on serum 25 hydroxyvitamin D level Deficiency <25nmol/L 1 st line: Colecalciferol 20,000unit capsule: Take 3 capsules once a week for 12 weeks 2 nd line: Colecalciferol 300,000unit IM injection: Give one immediately, repeat at 12 weeks 3 rd line: 300,000units in 100mL colecalciferol liquid: Take 50mL once a day for 2 days Insufficiency 25 50nmol/L Colecalciferol 1,000unit tablet: Take 1 2 tablets daily for 12 weeks Sufficient >50nmol/L Lifestyle and dietary advice Repeat levels at 12 weeks Has patient responded to treatment? Refer to appropriate specialist in secondary care Monitor patient every 12 months If patient considered still at risk give lifestyle advice or consider maintenance therapy 1 st line: calcium carbonate 1.5g & colecalciferol 400unit (10mcg) chewable tablet: Take 1 tablet twice a day 2 nd line: colecalciferol 1,000unit tablet: Take 1 tablet daily (only if patients have adequate dietary calcium intake or are at risk of hypercalcaemia)