I'm posting this to Lacnet as well as to Jennifer, in case others are
needing some references on this topic.

Early studies found that lactating mothers studied before the babies were 6
months or so old seemed to lose bone mass.  More recent, longer-term
studies show that after weaning there is a rebound effect, and increased
bone density. Longer lactation is even more beneficial, not less. Judy
Hopkinson, PhD spoke on this topic at the ILCA conference in New Orleans,
August 13, 1997.  She was with the USDA/ARS Children's Nutrition Research
Center at Baylor College of Medicine, 1100 Bates Street, Houston, TX
77030-2600  I thought her talk was very interesting.

Here are a few articles on the topic.  There may be some more recent ones
with even stronger findings.  I think this topic was discussed on Lactnet
recently, so check the archives, also.

Anderson JJB et al. Peak bone mass development of females: Can young adult
women improve their peak bone mass? J Am Coll Nutr 1996;15(6):570-574.

Blaauw E et al. Risk factors for the development of osteoporosis in a South
African population: A prospective analysis. S Afr Med J 1994;84:328-332.

Cross NA et al. Calcium homeostasis and bone metabolism during pregnancy,
lactation and postweaning: a longitudinal study. Am J Clin Nutr
1995;61:514-523.

Cross NA et al. Changes in bone mineral density and markers of bone
remodeling during lactation and postweaning in women consuming high amounts
of calcium. J Bone Miner Res 1995;10(9):1312-1320.

Cumming RG et al. Breastfeeding and other reproductive factors and the risk
of hip fractures in elderly women. Int J Epidemiol 1993;22(4):684-691.

Hopkinson J et al. Long-term changes in bone mineral density in lactating
and non-lactating women.  FASEB J 1997;11(3):A395.

Kalkwarf HJ. Calcium homeostasis and bone loss during lactation.
Breastfeeding Abstracts 1996;16(1):3-4.

Kalkwarf HJ et al. Intestinal calcium absorption of women during lactation
and after weaning.Am J Clin Nutr 1996;63:526-31.

Kalkwarf HJ et al. The effect of calcium supplementation on bone density
during lactation and after weaning. N Eng J Med 1997;337(8):523-528.

Lopez JM et al. Bone turnover and density in healthy women during
breastfeeding and after weaning.  Osteoporos Int 1996;6(2):153-159.

Prentice A. Calcium supplementation during breast-feeding. (Editorial). N
Engl J Med 1997;337(8):558-559.

Sowers M. Review: Pregnancy and lactation as risk factors for subsequent
bone loss and osteoporosis. J Bone Min Res 1996;11(8):1052-1060.

Sowers MF et al. A prospective study of bone density and pregnancy after an
extended period of lactation with bone loss. Obstet Gynecol
1995;85:285-289.

Tylavsky FA et al. Changes in radial and vertebral bone mass due to
pregnancy and lactation in humans. J Bone Min Res 1989;4(S1):S414.

Anne Altshuler, RN, MS, IBCLC and LLL leader in Madison, Wisconsin
mailto:[log in to unmask]

             ***********************************************
The LACTNET mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software together with L-Soft's LSMTP(TM)
mailer for lightning fast mail delivery. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html