Table 3 Prospective Observational Studies that met the Inclusion Criteria

Feskanich

1996

Women 35 to 59 years

Protein intake

Fractures

Protein intake was associated with increased risk of forearm fracture; no association between protein intake and hip fractures.

Age, BMI, change of BMI, estrogen status, smoking, energy intake, physical activity, calcium, potassium, and vitamin D intakes.

Family history of osteoporosis, baseline BMD

Munger

1999

Postmenopausal women

Protein intake

Hip fractures

Protein intake was associated with lower hip fracture risk.

Age, body size, parity, smoking, alcohol intake, estrogen use, physical activity

Weight loss during follow-up, family history of osteoporosis, baseline BMD, vitamin D status, calcium intake

Tucker

2001

Adults 69 to 97 years

Fruit & vegetable nutrients, & protein

Change of BMD

Potassium, fruit & vegetable intakes among men were associated with less BMD loss. Protein intakes were associated with less BMD loss.

Energy intake, age, sex, weight, BMI, smoking, caffeine, alcohol intake, physical activity, calcium intake, calcium and/or vitamin D supplements, season, current estrogen use.

Weight loss during follow-up, family history of osteoporosis, baseline BMD

Promislow

2002

Adults 55 to 92 years

Protein intake

Change of BMD

Protein intake was associated with increased BMD over 4 years.

Energy intake, calcium intake, diabetes, number

of years postmenopausal, exercise, smoking, alcohol,

thiazides, thyroid hormones, steroids, and estrogen,

body weight change

Family history of osteoporosis, baseline BMD

Kaptoge

2003

Adults 67 to 79 years

Fruit, vegetables, vitamin C

Change of BMD

No associations between nutrients and BMD loss. In women, vitamin C was associated with less BMD loss. No associations for fruit and vegetable intakes.

Sex, age, BMI, weight change, physical activity, smoking, family history, energy intake.

Baseline BMD, estrogen status, vitamin D status, calcium intake

Rapuri

2003

Women 65 to 77 years

Protein intake

Change of BMD

No association between protein intake and the rate of bone loss.

Age, BMI, intakes of calcium, energy, fiber, vitamin D status, and alcohol, smoking, physical activity.

Weight loss during follow-up, baseline BMD, family history of osteoporosis

MacDonald

2004

Premenopausal women

Fruit & vegetables nutrients

Change of BMD

Among menstruating and perimenopausal women, intakes of vitamin C and magnesium, but not potassium, were associated with change of BMD.

Age, weight, change in weight, height, smoking, physical activity, socioeconomic status, baseline BMD.

Family history of osteoporosis, calcium intake, vitamin D status

Dargent-Molina

2008

Postmenopausal women

Protein & diet acid load

Fractures

No overall association between protein intake and acid excretion with fracture risk; in the lowest calcium intake quartile, protein intake was associated with fracture risk

Age, BMI, physical activity, parity, maternal history of hip fracture, hormonal therapy, smoking, alcohol, energy intake.

Weight loss during follow-up, baseline BMD, vitamin D status.

Thorpe

2008

Peri- and Postmenopausal women

Protein

Wrist fractures

Protein intake was associated with lower risk of wrist fracture, for both vegetable and meat protein.

Age, height, weight, BMI, education, any fracture since age 35, parity, smoking, alcohol use, diabetes mellitus, rheumatoid arthritis, physical activity, years since menopause.

Estrogen status, calcium intake

Pedone

2009

Women 60 to 96 years

Potential renal acid load

Change of BMD

Protein intake was associated with a lower loss of BMD.

Physical activity, energy intake, renal function, vitamin D status, estrogen status, baseline BMD.

Weight loss during follow-up, family history of osteoporosis, calcium intake.

Beasley

2010

Women 14 to 40 years

Protein intake

Change of BMD

No association between protein intake and change of BMD.

Age, race-ethnicity, age of menarche, time since menarche, family history of fracture, BMI, physical activity score, calories, dietary calcium, phosphorous, dietary vitamin D, magnesium, fluoride, alcohol, smoking, contraceptive use, prior pregnancy, and education

Fenton

2010

Adults 25 years+

Urine pH, urine potassium, sodium, calcium, magnesium, phosphate, sulfate, chloride, and acid excretion, controlled for urine creatinine

Change of BMD and fractures

No associations between urine pH or acid excretion and either the incidence of fractures or change of BMD

Age, gender, family history of osteoporosis, BMI, change in BMI, baseline BMD, estrogen status, kidney disease, smoking, thiazide diuretics, bisphosphonates, physical activity, calcium intake, and vitamin D status, urine creatinine,.