以國民營養健康狀況變遷調查2013-2020年之資料探討鈣、維生素D和鎂對老人骨質健康之影響

Abstract

鈣質是造骨的最基本元素，每天要攝入多少鈣及其他相關營養素，才能維護骨質最佳狀態，是極為重要的營養議題；然而臺灣訂定鈣膳食參考攝取量，主要仰賴歐美的專家報告，由於不同人種之遺傳、飲食及生活型態差異大，亟需我國本土研究實證資料；此外鈣的利用還受到鎂及維生素D、身體發炎狀態的影響，國人到底需要多少鈣質及相關營養素飽受爭議；此外兒童青少年之骨本建立與老人之骨密維持議題需分別探討。本研究針對骨質疏鬆議題，使用2013-2020之國民營養健康狀況調查老人資料共2179筆，進行多變量回歸分析探討骨密相關營養素與骨質密度（應變項）之關係；股骨頸和腰椎之骨密度由DEXA測得，飲食鈣和鎂攝取量由簡易頻率問卷計算，血清維生素D以電化學冷光免疫分析法測得。結果顯示，總鈣攝取量對65歲以上老人之股骨頸及腰椎骨密度沒有統計上的影響；每天攝取超過628毫克的非乳鈣者（第五分位）骨質密度與其他四分位比較顯著最低，然而乳鈣攝取量與骨密度亦沒有相關性。值得注意的是，適量的乳鈣（107 - 438 mg/d）與較高的股骨頸骨密度相關。鎂平均攝取接近每日營養素建議量的組別相較於攝取量較少者，有顯著較高的骨密度。另外血清維生素D濃度達到足量30 ng/mL以上其股骨頸與腰椎骨密度也會越高。由本研究推論，當下鈣質攝取量對台灣老人骨密狀況並非關鍵，適當的鎂與維生素D營養之重要性可能更為重要。

Calcium is a critical component of bone formation. The Taiwanese dietary reference intake for calcium referenced on several Western countries’ Daily Reference Intakes. The findings of these countries might not be applicable to the Taiwanese population owing to genetic, environmental, and dietary differences. It is still controversial whether Taiwanese should eat as much calcium as the Western country; therefore, the present study aims to investigate the calcium effect on bone mineral density (BMD) among elders, especially considering the combined effect of magnesium and vitamin D, two essential elements for bone health. Of 2849 participants aged above 65y and underwent DXA examination from the 2013-2020 Nutrition and Health Survey in Taiwan, 2179 were included in our study. Daily dietary calcium and magnesium intakes were collected from a simplified Food Frequency Questionnaire, and serum 25(OH)D was analyzed by Electrochemiluminescence immunoassay. Femoral neck and lumbar spine BMD (FN BMD & LS BMD) were examined by DEXA. The multivariate regression model was used to understand the association between calcium, vitamin D, magnesium, and BMD. Our results showed that higher dietary magnesium intake (over 424 mg/d) and sufficient serum 25(OH)D (over 30 ng/ml) were significantly and positively associated with FN BMD and LS BMD, while total calcium intake level was not in Taiwanese elders above 65y. People with over 628 mg/d of non-dairy Ca at the fifth quintile had the least bone density compared to other 4 quintiles. On the other hand, dairy calcium intake was not associated with BMD.