- Email: [email protected]
Bespoke or one size fits all—Vitamin D fortification, targeted supplementation in risk groups or individual measurement?
Maturitas 103 (2017) 1–2
Contents lists available at ScienceDirect
Maturitas journal homepage: www.elsevier.com/locate/maturitas
Editorial
Bespoke or one size fits all—Vitamin D fortification, targeted supplementation in risk groups or individual measurement?
MARK
Vitamin D insufficiency is prevalent in Northern Europe, particularly in winter and spring given the low sunlight UVB intensity in winter months which precludes vitamin D production even if the skin is exposed. Though association studies have linked, in many cases controversially, low vitamin D status to an increased risk of outcomes, the least controversial effect of vitamin D is on the skeleton where calcium and vitamin D supplementation in combination modestly reduce the risk of fractures in the elderly population. Severe nutritional rickets or osteomalacia are unusual but by no means eradicated in Western Europe. Fortification of foods with vitamin D is most of all a precaution against severe rickets and probably cannot be tailored to safely optimize vitamin D levels in the entire population. The importance of avoiding very severe vitamin D deficiency is undisputed but most European countries have opted not to put in place mandatory food fortification programmes. The exception is infant forumula and follow-on formula, which must be vitamin D fortified according to EU law. In the Nordic countries, Sweden, Finland, and Iceland have elected to require fortification of certain foods. Hence, in Sweden and Iceland low-fat milks are fortified while Finland has vitamin D fortification of fat spreads, milk, and non-dairy milk alternatives [1]. In the United Kingdom, most margarines and fat spreads are in fact fortified with vitamin D though there is no longer a legal requirement to do so. Ideally, mandatory programmes aim to provide the public with a small amount of vitamin D – in the region of 5 ug per day – that is large enough to avoid nutritional rickets but not so large as to risk toxicity even in consumers with unusual dietary habits. Targeting the frail elderly with low caloric intakes is certainly difficult with this approach which may, depending on the fortification chosen, very well bypass those with the greater need and deliver the highest amounts to those already vitamin D replete. Effects may be confined to patients with marked insufficiency. It has recently been confirmed in the ViDA RCT that vitamin D supplementation – given in the form of 100,000 IU as a monthly oral dose- has no discernible effect on bone mass in those who do not have markedly reduced serum levels of 25-OHD [2], i.e. serum concentrations below ≤30 nmol/l. The dose given corresponds to 80 ug of D3 daily or eight times the current referent nutrient intake (RNI) in the UK SACN recommendation in Vitamin D. Studies with falls outcomes have generally disappointed, certainly for vitamin D monotherapy [3,4]. Vitamin D supplements should be targeted to risk groups but there is little evidence that this is being successfully implemented [5]. There is a clear role for vitamin D supplements in those who have compelling risk factors for vitamin D deficiency or whose vitamin D status has been measured and found to be low. Risk groups include nursing home residents and those who avoid sun exposure for cultural reasons, personal preferences, concomitant health issues or photosensitizing medications. Such risk groups could be candidates for supplementation without the need for measurement of vitamin D status. In others, unspecific symptoms such as fatigue, muscle weakness or muscle pain will lead to measurement of serum vitamin D status and start of supplementation if low. However, the large variation in prescribing vitamin D supplements, with little relation to geographical latitude or sociodemographic characteristics, that has recently been described in the UK suggests considerable lack of consensus between prescribers [5]. This may well be the case in other European countries, but the demographics are unclear as supplements are often purchased in health stores and supermarkets, or over the counter in pharmacies. There is no strong case for measuring serum 25-OHD in asymptomatic people without risk factors. It is true that vitamin D deficiency is an important health issue, that there is an effective treatment, and that the method of assessment – a blood sample – would generally be acceptable to the public. However, the accuracy of affordable vitamin D assays falls somewhat short of what could be desirable and though most clinicians would advocate vitamin D supplementation in persons with 25-OHD levels below 50 nmol/l, some prescribers would not intervene unless levels were below 25–30 nmol/l while others would intervene in those with levels below 75 nmol, i.e. the majority of North Europeans in the winter season. Also, studies are lacking that demonstrate that the cost of screening for vitamin D insufficiency in the population as a whole, even at Northern latitudes, would be money well spent in terms of improved patient outcomes (cost-utility). A path forward When advising our patients about vitamin D we should be aware that there are strong opinions among clinicians and in the general public about the importance of vitamin D for health and in particular skeletal health, yet in most people the benefits of such supplementation may be very modest. The case for adding small amounts of vitamin D to a broad range of food items is best at Northern latitudes and this would mainly be tailored to avoid nutritional rickets and osteomalacia in the most susceptible community members. There is certainly a case for supplementation in risk groups as http://dx.doi.org/10.1016/j.maturitas.2017.06.001 Received 23 May 2017 0378-5122/ © 2017 Published by Elsevier Ireland Ltd.
Maturitas 103 (2017) 1–2
Editorial
discussed above and for measurement of vitamin D status in those with symptoms and those presenting with what appears to be osteoporosis on DXA but which could be a reversible osteomalacia that would not benefit from antiresorptive drugs. Approaches may change as reliable vitamin D assays become more affordable but broad screening is not a viable strategy at present. Conflict of interests Institutional research contracts with UCB and Novartis. Contributor BA is the sole contributor. Funding None. Provenance and peer review Commissioned, not peer reviewed References [1] A. Spiro, J.L. Buttriss, Vitamin D: an overview of vitamin D status and intake in Europe, Nutr. Bull. 39 (4) (2014) 322–350. [2] I.R. Reid, A.M. Horne, B. Mihov, G.D. Gamble, S. Fenwick, C.A. Camargo Jr., A.W. Stewart, R. Scragg, RCT of monthly high-dose Vitamin D on bne density in community-dwelling older adults: trial-based evidence for defining Vitamin D deficiency (abstract), Calcif. Tissue Int. 100 (2017) (p. S21). [3] K.-T. Khaw, A.W. Stewart, D.W. Med, C.M.M.L. Mbchb, P. Les, T. Mbchb, P. Carlos, A.C.P. Robert Jr, S. Mbbs, Articles effect of monthly high-dose vitamin D supplementation on falls and non-vertebral fractures: secondary and post-hoc outcomes from the randomised, double-blind, Lancet Diabetes Endocrinol. 8587 (17) (2017) 1–10. [4] M.J. Bolland, A. Grey, I.R. Reid, Differences in overlapping meta-analyses of Vitamin D supplements and falls, J. Clin. Endocrinol. Metab. 99 (November) (2014) 4265–4272. [5] T.R. Hill, T.J. Aspray, Vitamin D prescribing in older people in the UK depends on postcode, Maturitas 99 (2017) 109–113. ⁎
Bo Abrahamsen,, Department of Medicine, Holbæk Hospital, Holbæk, Denmark Odense Patient Data Explorative Network, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark E-mail address: [email protected]
⁎
*Correspondence address: Department of Medicine, Holbæk Hospital, Holbæk, Denmark.
2
Contents lists available at ScienceDirect
Maturitas journal homepage: www.elsevier.com/locate/maturitas
Editorial
Bespoke or one size fits all—Vitamin D fortification, targeted supplementation in risk groups or individual measurement?
MARK
Vitamin D insufficiency is prevalent in Northern Europe, particularly in winter and spring given the low sunlight UVB intensity in winter months which precludes vitamin D production even if the skin is exposed. Though association studies have linked, in many cases controversially, low vitamin D status to an increased risk of outcomes, the least controversial effect of vitamin D is on the skeleton where calcium and vitamin D supplementation in combination modestly reduce the risk of fractures in the elderly population. Severe nutritional rickets or osteomalacia are unusual but by no means eradicated in Western Europe. Fortification of foods with vitamin D is most of all a precaution against severe rickets and probably cannot be tailored to safely optimize vitamin D levels in the entire population. The importance of avoiding very severe vitamin D deficiency is undisputed but most European countries have opted not to put in place mandatory food fortification programmes. The exception is infant forumula and follow-on formula, which must be vitamin D fortified according to EU law. In the Nordic countries, Sweden, Finland, and Iceland have elected to require fortification of certain foods. Hence, in Sweden and Iceland low-fat milks are fortified while Finland has vitamin D fortification of fat spreads, milk, and non-dairy milk alternatives [1]. In the United Kingdom, most margarines and fat spreads are in fact fortified with vitamin D though there is no longer a legal requirement to do so. Ideally, mandatory programmes aim to provide the public with a small amount of vitamin D – in the region of 5 ug per day – that is large enough to avoid nutritional rickets but not so large as to risk toxicity even in consumers with unusual dietary habits. Targeting the frail elderly with low caloric intakes is certainly difficult with this approach which may, depending on the fortification chosen, very well bypass those with the greater need and deliver the highest amounts to those already vitamin D replete. Effects may be confined to patients with marked insufficiency. It has recently been confirmed in the ViDA RCT that vitamin D supplementation – given in the form of 100,000 IU as a monthly oral dose- has no discernible effect on bone mass in those who do not have markedly reduced serum levels of 25-OHD [2], i.e. serum concentrations below ≤30 nmol/l. The dose given corresponds to 80 ug of D3 daily or eight times the current referent nutrient intake (RNI) in the UK SACN recommendation in Vitamin D. Studies with falls outcomes have generally disappointed, certainly for vitamin D monotherapy [3,4]. Vitamin D supplements should be targeted to risk groups but there is little evidence that this is being successfully implemented [5]. There is a clear role for vitamin D supplements in those who have compelling risk factors for vitamin D deficiency or whose vitamin D status has been measured and found to be low. Risk groups include nursing home residents and those who avoid sun exposure for cultural reasons, personal preferences, concomitant health issues or photosensitizing medications. Such risk groups could be candidates for supplementation without the need for measurement of vitamin D status. In others, unspecific symptoms such as fatigue, muscle weakness or muscle pain will lead to measurement of serum vitamin D status and start of supplementation if low. However, the large variation in prescribing vitamin D supplements, with little relation to geographical latitude or sociodemographic characteristics, that has recently been described in the UK suggests considerable lack of consensus between prescribers [5]. This may well be the case in other European countries, but the demographics are unclear as supplements are often purchased in health stores and supermarkets, or over the counter in pharmacies. There is no strong case for measuring serum 25-OHD in asymptomatic people without risk factors. It is true that vitamin D deficiency is an important health issue, that there is an effective treatment, and that the method of assessment – a blood sample – would generally be acceptable to the public. However, the accuracy of affordable vitamin D assays falls somewhat short of what could be desirable and though most clinicians would advocate vitamin D supplementation in persons with 25-OHD levels below 50 nmol/l, some prescribers would not intervene unless levels were below 25–30 nmol/l while others would intervene in those with levels below 75 nmol, i.e. the majority of North Europeans in the winter season. Also, studies are lacking that demonstrate that the cost of screening for vitamin D insufficiency in the population as a whole, even at Northern latitudes, would be money well spent in terms of improved patient outcomes (cost-utility). A path forward When advising our patients about vitamin D we should be aware that there are strong opinions among clinicians and in the general public about the importance of vitamin D for health and in particular skeletal health, yet in most people the benefits of such supplementation may be very modest. The case for adding small amounts of vitamin D to a broad range of food items is best at Northern latitudes and this would mainly be tailored to avoid nutritional rickets and osteomalacia in the most susceptible community members. There is certainly a case for supplementation in risk groups as http://dx.doi.org/10.1016/j.maturitas.2017.06.001 Received 23 May 2017 0378-5122/ © 2017 Published by Elsevier Ireland Ltd.
Maturitas 103 (2017) 1–2
Editorial
discussed above and for measurement of vitamin D status in those with symptoms and those presenting with what appears to be osteoporosis on DXA but which could be a reversible osteomalacia that would not benefit from antiresorptive drugs. Approaches may change as reliable vitamin D assays become more affordable but broad screening is not a viable strategy at present. Conflict of interests Institutional research contracts with UCB and Novartis. Contributor BA is the sole contributor. Funding None. Provenance and peer review Commissioned, not peer reviewed References [1] A. Spiro, J.L. Buttriss, Vitamin D: an overview of vitamin D status and intake in Europe, Nutr. Bull. 39 (4) (2014) 322–350. [2] I.R. Reid, A.M. Horne, B. Mihov, G.D. Gamble, S. Fenwick, C.A. Camargo Jr., A.W. Stewart, R. Scragg, RCT of monthly high-dose Vitamin D on bne density in community-dwelling older adults: trial-based evidence for defining Vitamin D deficiency (abstract), Calcif. Tissue Int. 100 (2017) (p. S21). [3] K.-T. Khaw, A.W. Stewart, D.W. Med, C.M.M.L. Mbchb, P. Les, T. Mbchb, P. Carlos, A.C.P. Robert Jr, S. Mbbs, Articles effect of monthly high-dose vitamin D supplementation on falls and non-vertebral fractures: secondary and post-hoc outcomes from the randomised, double-blind, Lancet Diabetes Endocrinol. 8587 (17) (2017) 1–10. [4] M.J. Bolland, A. Grey, I.R. Reid, Differences in overlapping meta-analyses of Vitamin D supplements and falls, J. Clin. Endocrinol. Metab. 99 (November) (2014) 4265–4272. [5] T.R. Hill, T.J. Aspray, Vitamin D prescribing in older people in the UK depends on postcode, Maturitas 99 (2017) 109–113. ⁎
Bo Abrahamsen,, Department of Medicine, Holbæk Hospital, Holbæk, Denmark Odense Patient Data Explorative Network, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark E-mail address: [email protected]
⁎
*Correspondence address: Department of Medicine, Holbæk Hospital, Holbæk, Denmark.
2