1 Division of Medication, College of Wisconsin College of Medication & Public Well being, Madison, WI
2 Pharmacy Follow Division, College of Wisconsin College of Pharmacy
4 Departments of Biostatistics and Medical Informatics and Inhabitants Well being Sciences, College of Wisconsin, Madison, WI
5 Osteoporosis Medical Middle and Analysis Program, College of Wisconsin-Madison
5 Osteoporosis Medical Middle and Analysis Program, College of Wisconsin-Madison
1 Division of Medication, College of Wisconsin College of Medication & Public Well being, Madison, WI
1 Division of Medication, College of Wisconsin College of Medication & Public Well being, Madison, WI
5 Osteoporosis Medical Middle and Analysis Program, College of Wisconsin-Madison
Summary
Introduction
Vitamin D deficiency is widespread in older adults, with latest research describing deficiency in 18–25% of grownup postmenopausal girls (1, 2). Vitamin D deficiency outcomes from a number of components together with insufficient solar publicity, decreased cutaneous vitamin D synthesis, poor diet and sure drugs and co-morbid ailments reminiscent of anticonvulsants and celiac sprue (3). The rising measurement of serum 25(OH)D in older individuals arises from an rising consciousness of the prevalence of hypovitaminosis D and the function of vitamin D in each the prevention and administration of osteoporosis (4). Nonetheless, the prevalence of hypovitaminosis D and its influence on well being is much less sure in adults beneath age 50 years.
Wholesome younger adults could develop vitamin D deficiency for a number of causes. First, the every day vitamin D consumption of younger adults is usually beneath the really helpful consumption of 200 worldwide models (IU) every day (5, 6). Second, younger adults spend much less time exterior than younger adults one decade in the past (7–9). Third, the rising use of sunscreen to scale back pores and skin injury or most cancers could lower or eradicate cutaneous vitamin D synthesis (8, 10, 11). Lastly, many younger adults drink carbonated drinks rather than milk, thereby reducing the consumption of each calcium and vitamin D and probably rising the chance of fracture (12).
Regardless of mounting proof that younger adults are in danger for vitamin D deficiency, no particular suggestions exist relating to analysis of their vitamin D standing. Such lack of tips could consequence from restricted data on both the influence of vitamin D on the event of peak bone mass (13–15) or the long-term security of accelerating serum 25(OH)D ranges in younger adults. Though epidemiologic information means that improved vitamin D standing could lower the chance of sure cancers and autoimmune ailments (16–18), a real cause-effect relationship has not been established. Measurement of serum 25(OH)D is expensive, with fees starting from $45 to $100. A questionnaire to determine individuals at excessive or low danger of vitamin D deficiency can be clinically helpful, significantly as there isn’t any consensus relating to the indications for measurement of 25(OH)D in younger adults.
Different teams have used questionnaires to detect hypovitaminosis D. One group queried topics on use of multivitamins, milk and different meals containing vitamin D (19) and revealed a constructive correlation between serum 25(OH)D ranges and multivitamin consumption. Nonetheless, topics didn’t document solar publicity. A examine in Icelandic girls demonstrated an affiliation between larger serum 25(OH)D ranges and sun-seeking and dietary habits, however the questionnaire itself was not revealed (20). Using inquiries to assess food plan and solar publicity, a 3rd group reported associations between serum 25(OH)D ranges and season of measurement, physique mass index, age, time spent indoors, dwelling in three southern states, vitamin D consumption and creatinine. Nonetheless, the examine was restricted to aged topics (21).
We hypothesized {that a} easy questionnaire may determine younger adults with a excessive and low chance of vitamin D deficiency. We designed a sequence of inquiries to assess use of vitamin D-containing dietary supplements, milk and solar publicity so as to take a look at this speculation.
Supplies and Strategies
Between January and Might 2004 we recruited 184 women and men between the ages of 18 and 40 years into the present examine. The needs of the examine have been two-fold. First, we wished to estimate the prevalence of vitamin D deficiency in younger adults. Second, we queried whether or not a questionnaire may determine topics at excessive or low danger of vitamin D deficiency. We excluded people with pre-existing circumstances affecting vitamin D and/or calcium metabolism together with liver or kidney illness, consuming issues, pores and skin ailments and use of oral corticosteroids, anticonvulsants, insulin or bisphosphonates. We paid volunteers $20 for the only examine go to and notified them of vitamin D take a look at outcomes by mail.
The Human Topics Committee of the College of Wisconsin authorised the examine protocol. Members acquired verbal and written descriptions of the examine, signed the consent kind and retained a replica for his or her data. We recorded the age, gender and self-reported race of every individual on the examine go to. Every topic accomplished a questionnaire designed to quantify consumption of vitamin D by way of food plan and solar publicity and to document the presence of circumstances or drugs identified to have an effect on vitamin D shops (Desk 1).
To measure 25(OH)D, we collected blood from non-fasting individuals (22) and transported samples, with out publicity to mild, to a central laboratory on the College of Wisconsin. Samples have been saved at −70 levels Celsius till evaluation. Subsequently, we measured serum 25(OH)D utilizing a Liaison chemiluminescence assay (DiaSorin Inc.; Stillwater, MN). The chemiluminescence assay is an correct, fast and exact technique for vitamin D measurement, correlating properly with conventional radioimmunoassay however overestimating ranges by 3.9 ng/ml when in comparison with excessive efficiency liquid chromatography (HPLC) (23–25). In a examine of 329 medical samples, the intra and inter-assay coefficients of variation for this assay are 8 to 13% and eight to fifteen%, respectively (25).
The exact reduce factors used to outline vitamin D adequacy, insufficiency and deficiency differ, relying on the assay utilized and the investigator. Nonetheless, many consultants use a 25(OH)D degree <30 ng/ml (75 nmol/L) to outline vitamin D insufficiency and a degree <16 ng/ml (40 nmol/L) to outline deficiency (3). For the needs of this examine, we used a serum 25(OH)D < 16 ng/ml to categorize people as vitamin D poor.
Outcomes
We recruited 184 topics for the examine. Two-thirds of topics (n=124) participated throughout winter and 33% (n=60) throughout the spring. Topics’ imply (SD) age was 24 (4) years whereas the median age and vary have been 22.4 years and 18 to 40 years, respectively. Over half of topics (53%, n=98) have been feminine and 90% (n=165) have been Caucasian (Desk 2). Imply (SD) serum 25(OH)D ranges have been 25 (11) ng/ml (vary, 4 to 52 ng/ml). Almost three in 4 topics (71%, n=130) had serum 25(OH)D ranges < 30 ng/ml and one in 4 (26%, n=48) topics have been vitamin D poor. Desk 2 summarizes your complete group’s solutions to the questionnaire. Members reported ingesting a median of 1.9 (1.5) every day servings of milk. Almost half of topics (46%, n=84) ingested a every day multivitamin however solely 6% (n=11) took a further vitamin D complement and three% (n=5) reported every day use of cod liver oil. Topics’ imply vitamin D consumption by way of milk was 188 (148) IU and thru dietary supplements was 77 (238) IU every day. Eighty-five % of responders (n=157) reported solar tanning, 88% (n=161) reported sunscreen use, 29% (n=53) reported over half-hour of solar publicity every day and 35% (n=64) reported tanning sales space use prior to now 12 months. A number of traits recognized topics extra prone to have vitamin D deficiency (Desk 3). People with vitamin D deficiency reported decrease milk consumption (1.2 vs. 2.1 servings, p<0.001). Topics with deficiency have been much less prone to report a suntan (71% vs. 90%, p<0.001) or use a tanning sales space (4% vs. 46%, p<0.001). People with vitamin D deficiency have been barely older (imply age 26.5 years vs. 22.9 years, p<0.001) and extra typically male (65% vs. 40%, p=0.005). Lastly, non-Caucasian people have been extra prone to be vitamin D poor than Caucasians (deficiency in 67% of non-Caucasians vs. 23% of Caucasians, p <0.001). We carried out univariate and multivariate logistic regression analyses to find out the chances ratio for vitamin D deficiency based mostly on particular person objects within the questionnaire (Desk 4). In univariate outcomes, older age and male gender conferred a larger odds ratio for vitamin D deficiency. We managed for age and gender in multivariate analyses for 2 causes. First, age and gender could themselves affiliate with differing dietary and sun-seeking habits. Second, different research disagree on whether or not older age and male gender are danger components for vitamin D deficiency (21, 26, 27). Outcomes from adjusted and unadjusted analyses have been comparable. In multivariate analyses, adults beneath the median age of twenty-two.4 years (OR 0.25, 95% CI 0.12–0.53), these reporting a suntan (OR 0.24, 0.09–0.63, 95% CI, p=0.004), tanning sales space use (OR 0.09, 95% CI 0.02–0.43, p=0.002) and every day ingestion of two or extra servings of milk (OR 0.21, 95% CI 0.09–0.48, p<0.001) have been much less prone to be poor. In distinction, people extra prone to be poor have been non-Caucasians (OR 5.50, 95% CI 1.35–22.41, p=0.02) and males (OR 3.44, 95% CI 1.60–7.37, p=0.002). We carried out extra univariate and multivariate analyses with out non-Caucasian topics (n=19); these analyses confirmed just about an identical findings (Desk 6).
We evaluated the sensitivity and specificity of the questionnaire as a screening take a look at for vitamin D deficiency (Desk 5). Three self-reported habits (suntan, tanning sales space use and ingesting two or extra every day servings of milk) discriminated between younger adults with and with out vitamin D deficiency. Utilizing a threshold of two out of three destructive responses for these habits, we obtained a sensitivity of 79% and a specificity of 78% for figuring out individuals with vitamin D deficiency. We obtained an analogous sensitivity (76%) and specificity (79%) when excluding non-Caucasian topics (Desk 7).Dialogue – “vitamin d questionnaire”
We hypothesized that, like different age teams, younger adults would generally have vitamin D deficiency. On this examine of 184 wholesome younger topics, 71% had serum 25(OH)D ranges <30 ng/ml and 26% have been clearly vitamin D poor, with 25(OH)D ranges beneath 16 ng/ml. Individuals with vitamin D deficiency could develop osteomalacia, a illness characterised by unmineralized osteoid resulting in bone ache and skeletal fragility. Greater vitamin D ranges are related to elevated bone mass (13-15, 28). Certainly, research recommend that stopping vitamin D deficiency could optimize calcium homeostasis and facilitate peak bone mass in younger adults (13, 14). The excessive prevalence of deficiency in younger adults highlights the necessity for additional analysis to determine the exact vitamin D degree wanted to optimize musculoskeletal well being. Such data will facilitate affected person training and public coverage, with the purpose of reaching vitamin D adequacy. We hypothesized {that a} questionnaire may determine younger individuals at excessive and low danger of vitamin D deficiency. A single query didn't reliably distinguish between these teams. Nonetheless, these topics who acquired a suntan, used a tanning sales space, or drank at the very least two servings of milk every day have been considerably much less prone to be poor than topics not reporting these habits. Together, these three objects have been helpful in differentiating between these with and with out vitamin D deficiency. For topics responding within the destructive to any two of those three questions, we obtained a sensitivity of 79% and specificity of 78% for predicting vitamin D deficiency. Though the questionnaire wants additional revision to enhance its efficiency, it seems that three questions could assist clinicians resolve whether or not to pursue laboratory testing for vitamin D deficiency. It isn't stunning that solar publicity and milk ingestion could shield towards vitamin D deficiency. Vitamin D fortification of milk is required in the USA, based mostly on analysis carried out a long time in the past on the College of Wisconsin. An 8 ounce glass of milk incorporates ~100 IU of vitamin D. Likewise, cutaneous solar publicity will increase 25(OH)D ranges, except sunscreen with a solar safety issue ≥15 is used (29). Moreover, many tanning beds emit ultraviolet B mild, which will increase vitamin D synthesis (20, 30, 31). Though sun-induced summer season increments in serum 25(OH)D step by step decline over the winter, girls with low vitamin D consumption however excessive summer season solar publicity could keep larger serum 25(OH)D ranges within the winter as properly (32). Whereas the reason for this statement is unknown, summer season solar publicity related in a single examine with improved vitamin D standing year-round (32). Few research have used questionnaires to foretell low serum 25(OH)D ranges. In a examine by Tangpricha et al., serum 25(OH)D ranges have been larger in topics taking multivitamins, however not larger in milk drinkers (19). Authors analyzed these associations between habits and serum 25(OH)D ranges (19), slightly than stratifying topics as adequate or poor as we did. Our vitamin D poor topics have been much less prone to take multivitamins in comparison with adequate topics (35% vs. 50%, p=0.08) however additional analyses confirmed no impact of multivitamin use on the chances of vitamin D deficiency. Milk consumption within the different examine was decrease (1.6 (1) serving every day) (19) than that reported by our topics, which could clarify why there was no distinction in vitamin D ranges between their topics who drank and didn't drink milk. In a questionnaire-based Icelandic examine, older girls consuming fish oil or multivitamins had larger serum 25(OH)D ranges (p<0.01) than youthful girls who didn't report these habits (20). Ladies whose used tanning beds (p=0.06) or traveled to hotter climates (p<0.01) additionally had larger 25(OH)D ranges (20). A 3rd examine demonstrated associations between serum 25(OH)D and season, physique mass index, age, time spent indoors, dwelling in southern states, vitamin D consumption and creatinine (21). Taken as a complete, many of those findings are similar to ours and recommend that questions on solar publicity and supplemental and dietary vitamin D consumption could also be universally helpful to determine people in danger for vitamin D deficiency.
Primarily based on bigger cross-sectional research (26), we don't consider that questions on age will show helpful to exclude or suspect vitamin D deficiency. Certainly, ours just isn't the primary examine to report vitamin D inadequacy in younger adults. In Iceland, youthful girls had decrease vitamin D ranges than older girls (20). Almost half of adolescent ladies in Maine had hypovitaminosis D at the very least as soon as throughout a three-year statement (33). Two-thirds of inside drugs residents had 25(OH)D ranges beneath 20 ng/ml throughout spring months in Oregon (34). Collectively these research point out that hypovitaminosis D is widespread in younger adults. One sudden discovering on this examine was that males have been extra probably than girls to be vitamin D poor. In giant epidemiology research, males usually have larger serum 25(OH)D ranges than girls (21, 26, 27). Nonetheless, different research have reported no gender distinction in 25(OH)D ranges (21, 35). Primarily based on our and different research, we don't consider gender is a helpful technique of figuring out individuals at larger danger of vitamin D deficiency. Strengths of our examine embody testing of people of each genders from ages 18 to 40 years and uniform measurement of serum 25(OH)D by a single assay. Examine weaknesses additionally exist. The primary is the recruitment of comparatively few, predominantly Caucasian, examine topics. Except for milk, we didn't question consumption of different meals which may include vitamin D; nevertheless, only a few different meals include significant doses of vitamin D (3, 36). Moreover, the chemiluminescent assay used for this examine could barely overestimate serum 25(OH)D when in comparison with the gold customary HPLC assay. We didn't document time of day within the solar, though it's identified that each season and time of day affect cutaneous vitamin D synthesis (37). We measured 25(OH)D ranges in late winter and early spring, a time of low solar publicity in Wisconsin (37). Thus, 25(OH)D ranges have been measured at a nadir in our topics, rising the chance of vitamin D deficiency. Extra analysis is required to refine the present questionnaire and supply cost-effective algorithms to determine people who profit from serum 25(OH)D measurement. Ideally, a bigger examine carried out in a single season would question topics about solar publicity, milk ingestion and consumption of meals (fatty fish, liver, eggs) and dietary supplements containing vitamin D. The examine must also assess physique mass index and smoking, given the upper danger of deficiency reported in overweight sufferers and people who smoke (21, 38, 39). Moreover, signs or indicators of vitamin D deficiency, reminiscent of proximal muscle weak point or tibial tenderness, would possibly enable higher identification of topics at excessive danger of deficiency (40). Ideally, a questionnaire modified from the one herein would offer a “score” with larger sensitivity and specificity for vitamin D deficiency. Such a software would show helpful in medical apply. Peak bone mass happens round age 30 (41, 42). Fashions point out that interventions to extend peak bone mass are simpler at stopping osteoporosis than interventions later in life (43). Early analysis means that improved vitamin D standing promotes peak bone mass (13, 14). If researchers verify the significance of vitamin D on peak bone mass, younger adults would profit from international vitamin D fortification of meals and drinks.Acknowledgments
References
“vitamin d questionnaire”