The Effect of Chymosin on the Intestinal Absorption of Calcium: A Randomized Controlled Cross-over Trial
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 125
- 试验地点
- 1
- 主要终点
- The effect of the intervention on the 24 hours urine excretion of calcium corrected for creatinine
研究概览
简要总结
An adequate calcium intake is important for bone turnover and the risk of developing osteoporosis. Yet many studies have documented that supplementation with calcium tablets are often associated with a poor compliance, therefore it is important to explore ways to better calcium influx.
Calcium consumed through dairy products must first be cleaved from the molecules which it is bound to before it can be absorbed. Chymosin is an enzyme which cleaves the protein binding between some amino acids in κ-casein. The reaction occurs after ingestion of milk and causes a process whereby the time the milk is staying gastrointestinal tract is extended, this can lead to enhanced uptake of calcium.
When the body's calcium balance is in equilibrium excretion in urine (24 h) in roughly the size of the intake, whereby a measurement of circadian urine excretion of calcium can determine the amount of calcium absorbed from the intestine.
The investigators want to clarify whether the addition of chymosin to milk increases calcium absorption. Secondary to explore issues of significance for this effect, including vitamin D status and amount of daily calcium intake and whether a change in calcium absorption has immediate effects on bone turnover (measured as plasma osteocalcin, bone specific alkaline phosphatase (BSAP), and the renal excretion of cross-linked N-terminal telopeptide of type 1 collagen (NTx/Cr) ratio) and on the parathyroid function (measured as PTH). Finally we will explore relations between bone mineral density (BMD) and the measured parameters (in terms of P-PTH, P-25OHD, P-1,25(OH)2D, P-osteocalcin, P-BSAP, and U-NTx/Cr).
详细描述
Background:
Osteoporosis is a frequent disease. Allegedly, more than 500,000 Danes are diagnosed with osteoporosis and, in consequence, seems every year more than 20,000 fractures. A number of factors are known to increase the risk of osteoporosis, including a low daily intake of calcium.
Several clinical trials with calcium supplements for adults (with or without simultaneous supplementation of vitamin D) have shown an increase in bone mineral density (Bone Mineral Density, BMD) and reduction the risk of fractures. Similarly, several studies have shown that high milk intake during childhood and adolescence may increase bone mass and reduce the risk of fractures later in life.
Since an adequate calcium intake is important for bone turnover and the risk of developing osteoporosis, it is important to explore ways to better calcium influx. Several studies have documented that supplementation with calcium tablets are often associated with a poor compliance - people do not remember to take the tablets. It is therefore desirable to find methods that can increase the intake of the amount of calcium which occurs naturally in the diet.
Calcium consumed through dairy products must first be cleaved from the molecules which it is bound to before it can be absorbed. Various methods have been tried to optimizing the amount of calcium absorbed from dairy products, including the addition of so called fructo-oligosaccharides (FOSS) and casein phosphopeptides (CPPs).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 25 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •A stable daily intake of calcium on estimated 500-1200 mg, of which dairy products are minimum 500 mg
- •Speak and read Danish.
- •Written consent after verbal and written information
排除标准
- •Known lactose intolerance / milk allergy
- •Use of calcium supplements in tablet or powder
- •Intake of vitamin D supplements exceeding 10 micro grams/day
- •A habitual dietary calcium intake exceeding 1200 mg/day
- •Impaired renal function (plasma creatinine >150 micro mol/L)
- •Impaired liver function (plasma ALT >200 U/L, alkaline phosphatase >400 U/L).
- •Previous or present malignancies(including metastases).
- •sarcoidosis or second granulomatous disease which has caused hypercalcaemia
- •Pregnancy, breastfeeding
- •Postmenopausal women
- •Disease or treatment with drugs known to affect calcium homeostasis, including diuretics, osteoporosis agents, lithium, steroids, etc..
- •Pledged due to chronic alcoholism.
- •Severe medical or social problems which makes it unlikely that the participant can complete the survey
- •Lack of willingness / desire to participate
研究组 & 干预措施
Drug A: Chymosin
A: 5 drops of Chymosin is added to ½ a liter of milk. This is to be consumed during breakfast.
干预措施: Drug A Chymosin (Dietary Supplement)
Drug B: Placebo
B: 5 drops of placebo (water) is added to ½ a liter of milk. This is to be consumed during breakfast.
干预措施: Drug B: Placebo (Dietary Supplement)
结局指标
主要结局
The effect of the intervention on the 24 hours urine excretion of calcium corrected for creatinine
时间窗: Two time two days over an eighteen days period
The effect of the intervention on the 24 hours urine excretion of calcium corrected for creatinine
次要结局
- The effect of plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels on the amount of calcium absorbed and the potential impact of chymosin(Two time two days over an eighteen days period)
- The immediate biological effects of the intervention on P-PTH, and bone turnover (P-osteocalcin, P-BSAP, U-NTX)(Two time two days over an eighteen days period)
- Relations between bone mineral density (BMD) and the measured parameters (P-25OHD, P-1,25(OH)2D), P-PTH, P-osteocalcin, P-BSAP, U-NTx/Cr)(Will be measured one time at one of the two time two days over an eighteen days period)