Bolland Mark J, Chiu Weldon W, Davidson James S, Grey Andrew, Bacon Catherine, Gamble Greg D, Reid Ian R
Osteoporosis Research Group, Department of Medicine, University of Auckland, Private Bag 92 019, Auckland, New Zealand.
N Z Med J. 2008 Nov 28;121(1286):63-74.
To explore the effects of seasonal variation on the diagnosis of vitamin D sufficiency and to determine whether age, gender, and ethnicity modify these effects.
21,987 adults had a measurement of serum 25-hydroxyvitamin D (25OHD) at Labplus, Auckland City Hospital, between January 2002 and September 2003, and sine curves were fitted for 25OHD versus day of year to predict the 25OHD nadir for each individual.
48% (range: 30-63%) of individuals had 25OHD <50 nmol/L in the month of measurement, but 63% were predicted to have 25OHD <50 nmol/L in late winter or early spring based on expected seasonal variation. The 25OHD levels required to ensure 25OHD levels >50 nmol/L throughout the year varied substantially by season (in summer at least 60-75 nmol/L), and tended to be higher in men than women, decrease with age, and vary with ethnicity. Mean 25OHD levels were very low (<40 nmol/L) in people of Indian, Middle Eastern, and African descent.
Seasonal variation in 25OHD affects the diagnosis of vitamin D sufficiency. Clinicians should consider the month of sampling when interpreting the results of 25OHD measurements. In New Zealand, a summertime 25OHD <60-75 nmol/L is generally required to ensure year-round 25OHD levels <50 nmol/L.
探讨季节变化对维生素D充足诊断的影响，并确定年龄、性别和种族是否会改变这些影响。
2002年1月至2003年9月期间，21987名成年人在奥克兰市医院的Labplus进行了血清25-羟基维生素D（25OHD）检测，并对25OHD与一年中的日期进行正弦曲线拟合，以预测每个个体的25OHD最低点。
48%（范围：30%-63%）的个体在检测月份的25OHD<50 nmol/L，但根据预期的季节变化，预计63%的个体在冬末或早春时25OHD<50 nmol/L。确保全年25OHD水平>50 nmol/L所需的25OHD水平因季节而异（夏季至少为60-75 nmol/L），男性往往高于女性，随年龄增长而降低，并因种族而异。印度、中东和非洲血统人群的平均25OHD水平非常低（<40 nmol/L）。
25OHD的季节变化会影响维生素D充足的诊断。临床医生在解释25OHD检测结果时应考虑采样月份。在新西兰，通常需要夏季25OHD<60-75 nmol/L才能确保全年25OHD水平<50 nmol/L。
