FAQs

FREQUENTLY ASKED QUESTIONS

We have gathered frequently asked questions and answers to help you, and your at-risk patients, to enhance your understanding of the need and function of vitamin D and Desunin®.

Show all answers
Hide all answers
  • Asymptomatic adult groups at risk of vitamin D insufficiency <sup>1,2</sup>

    Asymptomatic adult groups at risk of vitamin D insufficiency 1,2

    Up to 50% of adults in the UK are thought to have insufficient levels of vitamin D, and it is thought that at least 16% of UK adults have severe deficiency during winter and spring.3

    • All pregnant and breastfeeding women especially teenagers and young women. 
    • Older people aged 65+ 
    • People with low sun exposure e.g cover skin for cultural reasons, are housebound or confined indoors for long periods
    • People with darker skin because their skin is not able to make sufficient Vitamin D


    References

    1. Vitamin D: increasing supplement use in at-risk groups NICE guidelines [PH56] Published date: November 2014.  Available at Vitamin D: increasing supplement use in at-risk groups: https://www.nice.org.uk/guidance/ph56?unlid=6240267162015791218 
    2. DoH Guidance (Vitamin D Advice on supplements for at risk groups. Letter from the UK Chief Medical Officers.  Available at https://www.gov.uk/goverment/uploads/attachment_data/file/213703/dh_132508.pdf
    3. Pearce S & Cheetham. T Diganosis and management of vitamin D deficiency. BMJ. 2010; 340:b5664 

  • Other adult high risk groups

    Other adult high risk groups

    • People who follow a vegetarian or vegan diet1
    • Obese patients 2,3
    • Patients with malabsorption, short bowel, or cholestatic liver disease 4
    • Patients taking some medications, such as anticonvulsants, rifampicin, cholestyramine, highly active antiretroviral treatment (HAART) or glucocorticoids 4
    • Patients requiring antiresorptive treatments such as zoledronate or denosumab 5


    References

    1. Vitamin D deficiency including osteomalacia and rickets. Available at: www.patient.co.uk/health/vitamin-d-deficiency-including-osteomalacia-and-rickets.
    2. Hyppönen E & Power C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. American Journal of Clinical Nutrition. 2007; 85(3): 860-8.
    3. Scientific Advisory Committee on Nutrition. Update on vitamin D: position statement by the Scientific Advisory Committee on Nutrition. London: The Stationery Office, 2007. Available at: www.sacn.gov.uk/reports_position_statements/position_statements/update_on_vitamin_d_-_november_2007.html 
    4. Pearce S & Cheetham T. Diagnosis and management of vitamin D deficiency. BMJ. 2010; 340:b5664.
    5. National Osteoporosis Society. Vitamin D and bone health: A practical clinical guideline for patient management. April 2013.

  • How does vitamin D work?

    How does vitamin D work?

    Vitamin D comes in two important forms for human metabolism:1

    • Vitamin D2: The form found in plants (also called ergocalciferol)
    • Vitamin D3: The form found in animals (also called colecalciferol)

    Vitamin D3 is produced in our skin in response to ultraviolet B (UVB) rays from the sun.1 Vitamin D2 is found in some plants in our diet and can be produced commercially for fortification of foods. Both forms of vitamin D are used for supplementation1, but studies indicate that vitamin D2 is much less potent and has a shorter duration of action than cholecalciferol.2,3,4

    Vitamin D3 (cholecalciferol) is converted to 25-hydroxycolecalciferol [25(OH)D or calcidiol] in the liver.1 In the kidneys 25(OH)D is hydroxylated to 1,25-dihydroxyvitamin D [1,25 (OH)2D or calcitriol] - the active form of vitamin D which is released back into the blood stream.1

    1,25(OH)2 D3 functions through a single vitamin D receptor.5 1,25(OH)2 D acts primarily on the duodenum, regulating how the body uses calcium and phosphorus.1,6 However, vitamin D receptors are present in many of the body's tissues5, including cells of the pancreas, immune system, macrophages, vascular endothelium, stomach, epidermis, colon, muscles and placenta.1

    The characteristics of 1,25 (OH)2D are those of a hormone, and so vitamin D is considered a prohormone rather than a true vitamin.1

    References 

    1. Thatcher T & Clarke B. Vitamin D insufficiency. Mayo Clinic Proceedings, 2011; 86(1):50-60. Available at: www.ncbi.nlm.nih.gov/pmc/articles/PMC3012634/
    2. Tjellesen L, Hummer L, Christiansen C, Rødbro P. Serum concentration of vitamin D metabolites during treatment with vitamin D2 and D3 in normal premenopausal women. Bone Miner. 1986 Oct;1(5):407-13.
    3. Trang HM, Cole DE, Rubin LA, Pierratos A, Siu S, Vieth R.  Evidence that vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2. Am J Clin Nutr. 1998 Oct;68(4):854-8.
    4. Armas LA1, Hollis BW, Heaney RP. Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004 Nov;89(11):5387-91.
    5. DeLuca H. Overview of general physiologic features and functions of vitamin D. Am J Clin Nutr, 2004; 80:1689-96.
    6. Holick M. Vitamin D: a D-Lightful health perspective. Nutrition Reviews, 2008; 66(2):182-194.
  • Why is vitamin D important?

    Why is vitamin D important?

    The best understood role for 1,25 (OH)2D (calcitriol) is in the control of how the body uses calcium and phosphorus to make strong bones.1 The body continually works to maintain serum calcium levels within tight margins.2 In a vitamin D insufficient state, the body becomes inefficient at absorbing intestinal calcium, affecting the balance of serum calcium levels. In an attempt to restore serum calcium levels, the body enhances tubular reabsorption of calcium in the kidneys and mobilisation of the calcium stores from the skeleton.2 Pre-osteoclasts stimulate the formation of multi-nucleated osteoclasts to dissolve the bone collagen matrix and release calcium stores into the circulation.2

    The increased activity of osteoclasts and loss of calcium from the bone matrix results in destruction of the skeleton leading to rickets in children, and osteomalacia and osteoporosis in adults, increasing the risk of fractures in these patients.1,2

    References 

    1. DeLuca H. Overview of general physiologic features and functions of vitamin. D. Am J Clin Nutr, 2004; 80:1689--96.
    2. Holick M. Vitamin D: a D-Lightful health perspective. Nutrition Reviews, 2008; 66(2):182--194.

  • What are the main sources of vitamin D?

    What are the main sources of vitamin D?

    Our most important natural source of vitamin D is innate production through solar ultraviolet B radiation which penetrates the skin and converts 7-dehydrocholesterol to 25(OH)D (calcidiol), which is then rapidly converted to 1,25 (OH)2D (calcitriol). During summer months, 15 minutes of whole body exposure to midday sunlight provides approximately 10,000 IU vitamin D3 in fair-skinned individuals.1

    However, for four to six months of the year, a large part of Europe receives insufficient UV-B radiation from sunlight for the production of vitamin D to occur.2

    Few foods naturally contain or are fortified with vitamin D, and the typical diet in Western Europe provides less than 10% of the daily vitamin D requirement.3

    Notes 

    Exposure to sunshine should always be moderated to avoid sun damage. 

    References 

    1. Cannell JJ et al. Diagnosis and treatment of vitamin D deficiency. Expert Opinion. Pharmacotherapy, 2008; 9(1):1-12.
    2. Webb et al. Influence of season and latitude on the cutaneous synthesis of vitamin D3: Exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. J Clin Endocrin Metab 1988; 67(2):373-78.
    3. Wagner et al. Breastfeeding Med. 2008; 3(4):239-46.

  • What are the symptoms of low levels of vitamin D?

    What are the symptoms of low levels of vitamin D?

    Vitamin D insufficiency
    Vitamin D insufficiency can be easily overlooked - patients can be asymptomatic or have vague symptoms such as tiredness or general aches.1,2

    Vitamin D deficiency
    Musculoskeletal pain and weakness are typical symptoms of vitamin D deficiency in adults.1 

    References 

    1. Pearce S & Cheetham T. Diagnosis and management of vitamin D deficiency. BMJ. 2010; 340:b5664.
    2. Vitamin D deficiency including osteomalacia and rickets. Available at: www.patient.co.uk/health/vitamin-d-deficiency-including-osteomalacia-and-rickets

  • What are the long-term consequences of vitamin D deficiency in adults?

    What are the long-term consequences of vitamin D deficiency in adults?

    The long-term consequences of low vitamin D status can be very serious. Protracted vitamin D deficiency causes impaired bone health, which can cause osteomalacia in adults.1 In adults, vitamin D deficiency can also lead to osteopenia / osteoporosis and increase risk of fracture.2 Pregnant women should maintain good levels of vitamin D to build adequate foetal stores for early infancy.3 

    A low level of vitamin D is associated with poor muscle strength and balance which may lead to an increasing tendency to fall in some patients.4 

    References

    1. Vitamin D deficiency including osteomalacia and rickets. Available at: www.patient.co.uk/health/vitamin-d-deficiency-including-osteomalacia-and-rickets (accessed 10 August 2015).
    2. Holick M. Vitamin D: a D-Lightful health perspective. Nutrition Reviews, 2008; 66(2):182-194.
    3. DoH Guidance (Vitamin D advice on supplements for at risk groups. Letter from the UK Chief Medical Officers. Available at www.gov.uk/government/uploads/system/uploads/attachment_data/file/213703/dh_132508.pdf
    4. Bischoff-Ferrari H et al. Effect of vitamin D on falls: a meta-analysis. JAMA, 2004; 291(16):1999-2006.

  • How much vitamin D is enough?

    How much vitamin D is enough?

    A 25(OH)D (calcidiol) level above 30 nmol/l is sufficient to prevent severe hypovitaminosis D, and in most cases osteomalacia and rickets. 1-3

    A calcidiol level of 50 nmol/l may be considered adequate 4 

    nmol/LVitamin D Status
    >50Sufficient for almost the whole population
    30-50May be inadequate in some people
    <30Deficient

    Table adapted from National Osteoporosis Society. Vitamin D and bone health: A practical clinical guideline for patient management. April, 20131

    References

    1. National Osteoporosis Society. Vitamin D and bone health: A practical clinical guideline for patient management. April 2013.
    2. Zittermann A et al. Putting cardiovascular disease and vitamin D insufficiency into perspective. Br J Nutr 2005;94:483-92.
    3. Souberbielle JC et al. Evaluating vitamin D status. Implications for preventing and managing osteoporosis and other chronic diseases. Joint Bone Spine 2006;73:249-53.
    4. Pearce S & Cheetham T. Diagnosis and management of vitamin D deficiency. BMJ. 2010; 340:b5664.

  • What is the correct dose of vitamin D?

    What is the correct dose of vitamin D?

    Daily dosing has been shown to provide more sustainable improvements to vitamin D status than large intermittent doses (annual or quarterly doses).1,2 The NOS cautions3 large doses of vitamin D given intermittently may be ineffective and may increase fracture risk. 

    In order to obtain an adequate level of vitamin D, individual patients may require very different doses.3 Dosing should therefore be tailored to the individual needs of each patient.

    The reasons for the variance in patient response to oral vitamin D supplementation include: malabsorption, augmented speed of elimination due to certain drugs, compliance, as well as starting base-line level of 25(OH)D (calcidiol).2,4-6 Obesity has been suggested as a limiting factor as vitamin D may be sequestered in adipose tissue.3

    Patients in need of rapid correction of vitamin D levels can be given a daily loading dose which should not exceed 4000IU per day7, to provide a total of approxiately 300,000IU over a 10 week period.3,7 e.g. 4000IU per day for 10 weeks (280,000IU) followed by 800IU - 2000IU daily one month after the loading dose has been completed.3

    Patients who do not require such rapid correction of deficiency, for example those at risk of vitamin D insufficiency, can be prescribed a daily maintenance dose.3 e.g. 800 - 2,000IU daily.3 

    References 

    1. Sanders KM et al. JAMA. 2010;303:1815-22.
    2. Pekkarinen T et al. Vitamin D3 treatment of elderly people. Clinical Endocrinology, 2010. 72(4):455-461.
    3. National Osteoporosis Society. Vitamin D and bone health: A practical clinical guideline for patient management. April 2013.
    4. Cannell JJ et al. Diagnosis and treatment of vitamin D deficiency. Expert Opinion. Pharmacotherapy, 2008; 9(1):1-12.
    5. Pearce S & Cheetham T. Diagnosis and management of vitamin D deficiency. BMJ, 2010; 340:b5664.
    6. Heaney RP et al. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. Am J Clin Nutr 2003; 77:204-10.
    7. Scientific Opinion on the Tolerable Upper Intake Level of Vitamin D. EFSA Journal 2012;10(7):2813

  • What is the difference between Desunin<sup>®</sup> and unlicensed vitamin D supplements/specials?

    What is the difference between Desunin® and unlicensed vitamin D supplements/specials?

    Desunin® is a licensed, prescription-only medicine.1,2

    As a licensed product, Desunin® offers a reliable therapeutic solution for treating vitamin D insufficiency and deficiency.1 Each Desunin® tablet contains 800 IU or 4000IU of vitamin D1,2 and has been manufactured to good manufacturing practice standards for the pharmaceutical industry. Desunin® is stringently quality controlled at all stages of production, packaging and shipping providing a consistent and predictable level of quality. 

    Vitamin D supplements available without prescription from pharmacies, shops and over the internet have not been evaluated or authorised before being introduced to the consumer market.

    References

    1. Meda Pharmaceuticals Ltd. Desunin. Summary of Product Characteristics. April 2012. Avaliable at https://www.medicines.org.uk/emc/medicine/27007.
    2. Meda Pharmaceuticals Ltd. Desunin 4000IU. Summary of Product Characteristics. Oct 2015. Avaliable at https://www.medicines.org.uk/emc/medicine/32123