Balance studies:

n=60 girls and 39 boys; aged 2–8 y; normal and healthy (Matkovic, 1991; Matkovic and Heaney, 1992)

Retention studies:

1. n=115 girls and 113 boys; aged 9–19 y (Martin et al., 1997)

2. n=80; aged 12–15 y; Caucasians (Greger et al., 1978; Jackman et al., 1997; Matkovic et al., 1990)

3. n=111 girls and 22 boys; aged 9–17 y; normal and healthy (Matkovic and Heaney, 1992)

BMC studies:

1. n=94 Caucasian girls; mean age 12 y (Lloyd et al., 1993)

2. n=48 Caucasian girls; mean age 11 y (Chan et al., 1995)

3. n=70 pairs of identical twins; aged 6–14 y; 45 pairs completed the 3-y study (Johnston et al., 1992)

n=26 men and 137 women; aged 18–30 y; normal and healthy (Matkovic and Heaney, 1992)

Balance studies:

1. n=130 premenopausal women (white Roman Catholic nuns); aged 35–50 y (Heaney et al., 1977)

2. n=25 healthy women; aged 30–39 y (Ohlson et al., 1952)

3. n=34 healthy women; aged 40–49 y (Ohlson et al., 1952)

BMD studies:

1. n=37 premenopausal women; aged 30–42 y (Baran et al., 1990)

2. n=49 premenopausal, healthy women; aged 46–55 y; Netherlands (Elders et al., 1994)