Calcium and vitamin D – Role in Musculoskeletal Health

Bess Dawson-Hughes, M.D.

How to understand the absorption of calcium correctly？

Calcium

Ca intake absorption Vitamin D

Ca++ Muscle str.

PTH Falls

Bone remodeling

           Bone loss Fracture risk

Mechanisms of Intestinal Calcium Absorption

Hoenderop J, et al. Physiol Rev. 2005;85:373-422.

Bullamore R. Lancet 1970; 2: 535-7.

What is the calcium intake that leads to maximal calcium

retention in bone?

Forbes, 1979

Intake (mg/day)

% M

axim

al r

eten

tio

n

200

300

100

0

-100

Linda and George McCabe, Purdue University, with permission

300

200

100

0

-100

-200

0 500 1000 1500 2000 2500

Calcium absorption from different calcium salts were similar to whole milk

39

32 3230

2731

0

5

10

15

20

25

30

35

40

45

Carbonate Lactate Acetate Ci trate Gl uconate Whol e mi l k

Sheikh MS, et al. N Eng J Med,1987,317(9):532-6

Net

Cal

cium

abs

orpt

ion（

%）

Intestinal Absorption of Calcium from Different Calcium Salts

Harvey JA, et al. J Bone Miner Res 1988; 3: 253-8.

Calcium Absorption in Relation to Dose

Bo-Linn GW, et al. J Clin Invest,1984,73:640-7.

Calcium Absorption in Relation to Gastric Acid Secretion

Heaney RP, et al. Am J Clin Nutr 1989; 49: 372-6.

Calcium Absorption in Relation to Meal

Effect of Oral Amino Acids on Absorption of Calcium

Civitelli R et al. Nutrition 1992; 8(6):400-405

Amino acid chelated calcium & Carbonate calcium

Search: MEDLINE 2004-2006•  • #1 0 osteoform• #2 30345 calcium• #3 0 osteoform and calcium• #4 64802 amino• #5 136334 acid• #6 172 chelated• #7 30345 calcium• #8 0 amino acid chelated calcium• #9 1531 carbonate• #10 30345 calcium• #11 583 carbonate calcium

•  

Search: MEDLINE 1999-2003• 

•#1 0 Osteoform

•#2 147398 amino

•#3 288313 acid

•#4 345 chelated

•#5 64534 calcium

•#6 0 amino acid chelated calcium

•#7 2473 carbonate

•#8 64534 calcium

•#9 855 carbonate calcium

Lead Content of Calcium Supplements

Supplement

category

Lead content, g/

800 mg calcium

Refined 0.92 0.56

Dolomite 4.17 2.02

Natural source 6.05 4.63

Bone meal 11.33 12.46

Milk 0.71 0.32

Borgoin BP, et al. Am J Pub Health 1993.

Effect of Increasing Calcium Intake on PTH and Bone Turnover in Women

Elderly Young

Normal Ca High Ca

Calcium Intake (mg/d)

813 2,414 918

PTH (pmol/L) 3.41a 2.18 2.01

Urine pyridinoline/Cr 51.7b 43.1 43.7

a Differs from other groups, p < 0.001

b Differs from other groups, p < 0.05

McKane WR et al. J Clin Endocrinol Metab 1996; 81(5):1699-1703.

Shea B, et al. Endocrine Rev . 2002,23(4):552-559.

Calcium Supplementation for the Prevention of Postmenopausal Osteoporosis ： a meta-analysis

Calcium supplementation in women older than 45 yr with absence of menses for a minimum of 6 months; Treatment with doses of calcium at least 400 mg/d. The maintenance dose of vitamin D was no more than 400 IU/d

Weighted mean difference for lumbar spine after treatment with calcium at 2 yr.

Calcitonin, Calcium and Vertebral Fracture Risk – MEDOS Study

Kanis JA. Br Med J 1992; 305; 1124-28.

*

*P=0.01

0

0.5

1

Calcitonin Calcium Ca + Calcitonin

0.630.820.78

Ris

k R

atio

Fracture Prevention Trials: Calcium and Vitamin D Use and Results

Drug/Study Ca, mg/d Vit D, IU/dFracture risk

reduction (RR)

Alendronate

Liberman ‘95 500 0 0.5

Black ‘96 500* 250 0.5

Cummings ‘98 500* 250 0.6

Risedronate

Harris ‘99 1,000 500† 0.6

Raloxifene

Ettinger ‘99 500 400-600 0.7

* If dietary calcium < 1,000 mg † If 25(OH)D level < 40 nmol/L

Calcium Intake in Elderly Chinese Women

Vegetarian (N=179)

Omnivore (N=250)

Age 81.3 70.7

Calcium, mg/1000 kcal 328 221

Potassium, mg/1000 kcal 914 783

Woo J et al. Age and Ageing 1998; 27:455-461.

Magnesium – Research Progress

• Mg depletion studies have been done in rats.

• Several epidemiologic studies have found positive associations between magnesium intake and bone mass and negative associations with diabetes and stroke.

Magnesium Depletion and the Skeleton in Rats

Diet % Nutrient Requirement Outcome

50a ↓ trabec vol, ↑osteoclast #

25b also ↑TNF-alpha

10c also ↑TNF-alpha

a Rude R. OI 2006; on-line.b Rude, R. Bone 2005; 37:211-219.

c Rude R. J Nutr 2004; 134:79-85.

Magnesium Intake – Associations with Diabetes and Stroke

Diabetesa

In >100,000 subjects followed for 12 to 18 yrs: High vs. low quintile RR 0.66 [0.60 –

0.73]

Strokeb

In 43,738 men followed for 8 yrs:

High vs. low quintile RR 0.62 [0.43, 0.88]

a Lopez-Ridaura R et al. Diabetes Care 2004; 27(1):134-140.b Ascherio A et al. Circulation 1998; 98(12):1198-204.