Joanne M. Foody 布莱根妇女医院心内科医生，致力于心脏病的预防和康复，研究领域为妇女心脏病

　　The data on Vitamin D supplementation and CVD risk are scant. However， large epidemiological studies suggest a relationship between low vitamin D on hypertension (the major cause of AF)， heart failure and general CVD risk. Mechanisms for this are still unclear.
　　An ongoing trial， The VYTAL trial， will address this issue.
　　For now， it is only recommended to replace Vitamin D in a deficiency only. Generally a level below 30mg/dL is deemed a deficiency. In our lipid clinic， located Boston， a latitude above 35 degrees with inadequate sun exposure throughout the winter months)， we obtain serum 25(OH)D on all patients with any complaints of generalized myalgias， joint pain， weakness or fatigue during any time of year. We use this as part of our workup of secondary causes of myalgias.
　　With new data showing the association of vitamin D deficiency with increased cardiovascular risk， we are also including it as part of our initial assessment of our high and intermediate risk cardiovascular patients. We have frequently seen vitamin D levels in the deficient and insufficient ranges since we started regular screening.
　　The standard recommendation for treatment of vitamin D deficiency is 50，000 IU of vitamin D2 (ergocalciferol) once weekly for 8 weeks and repeat for another 8 weeks if 25(OH) D <30ng/mL.5 We have utilized this recommendation to treat with prescription D2 but found that levels of 25(OH) D increased very slowly and many times needed renewal
We are finding improved 25(OH)D levels with vitamin D3 supplements within 8 weeks. Once levels of 32–50 ng/mL of 25(OH)D are achieved， 1000-2000 IU daily of vitamin D3 is usually needed for maintenance in the absence of sun exposure or inability to maintain adequate 25(OH)D levels for another 6–8 weeks.
　　As an alternative， we have managed patients with vitamin D deficiency with over-the-counter vitamin D3 (cholecalciferol) 5，000 IU daily for 8 weeks and continue an additional 8 weeks if levels do not rise above 30 ng/mL. We are finding improved 25(OH)D levels with vitamin D3 supplements within 8 weeks. Once levels of 32–50 ng/ mL of 25(OH)D are achieved， 1000-2000 IU daily of vitamin D3 is usually needed for maintenance in the absence of sun exposure or inability to maintain adequate 25(OH)D levels. Doses are adjusted based on serum 25(OH)D levels for patients who are overweight， obese or darker in pigmentation who may need increase in D3 dose. Our goal is to maintain levels of 25(OH)D between 35–90 ng/mL. For patients with past history of vitamin D deficiency/insufficiency， we plan to assess at least once yearly during winter months. Generally， we find many patients have significant improvement in symptoms， including reduction in myalgias， muscle fatigue and cramping as well re duction in generalized fatigue.

　　有关维生素D补充和心血管风险的研究数据相当缺乏。但是，大型流行病学研究提示，低维生素D摄入和高血压（导致心房颤动的主要病因）、心力衰竭和总体心血管风险之间存在相关性。不过其机制还不明确。一项正在进行中的研究VYTAL试验就是针对这一问题。
　　目前，仅在维生素D缺乏的情况下推荐补充维生素D。缺乏的定义为维生素D水平低于30 mg/dl。波士顿血脂诊所纬度在35度以北，整个冬天日照不足，我们给所有在一年当中任何时候主诉肌肉痛、关节痛、无力或疲劳的患者测定血清25-羟维生素D。我们将这一测定作为发现继发肌肉痛病因的手段。
　　新的数据显示维生素D缺乏和心血管风险增加之间具有相关性，因此我们将维生素D测定作为高危和中危心血管患者最初评价的一部分。在我们开始常规筛查维生素D之后，我们经常发现有些患者的维生素D水平处于缺乏和不足的范围之内。
　　维生素D缺乏的标准治疗方法是50 000 IU的维生素D2（钙化醇），每周一次，共8周；如果25-羟维生素D<30 ng/ml的话，再继续服用8周。我们采用这一方案进行维生素D2治疗，但是发现25—羟维生素D的水平升高得非常缓慢，很多情况下需要再次治疗。
　　我们发现补充维生素D3在8周内可以升高25-羟维生素D水平。一旦25-羟维生素D达到32～50 ng/ml，在没有日照或无法再维持6～8周的足够25-羟维生素D水平的话，通常需要给予1000～2000 IU/d的维生素D3补充来维持。
　　作为一种替代治疗手段，我们给维生素D缺乏的患者非处方的维生素D3（胆钙化醇）5 000 IU/d，共8周治疗，如果25-羟维生素D未达到30 ng/ml以上时，再治疗8周。我们发现，维生素D3补充8周内25-羟维生素D水平即得到改善。一旦25-羟维生素D的水平达到32～50 ng/ml，在没有日光照射或无法维持足够的25-羟维生素D水平时，通常需要给予1000～2000 IU的维生素D3来维持。对于超重、肥胖或色素沉积等可能需更大剂量维生素D3的人群，根据血清25-羟维生素D水平来调整药物剂量。我们的治疗目标是使25-羟维生素D维持在35～90 ng/ml。对于既往存在维生素D缺乏/不足病史的人群，我们计划每年冬天至少评估一次。通常来讲，我们发现很多患者的症状显著改善，包括减少肌肉痛、肌肉疲劳和痉挛改善，同时总体疲劳感也得到减轻。