Wednesday, September 26, 2007

Vitamin D supplementation in early pregnancy may help prevent preeclampsia

Vitamin D deficiency early in pregnancy is associated with a five-fold increased risk of preeclampsia, according to a new study published in the Journal of Clinical Endocrinology and Metabolism.

In newly published research, scientists evaluated data and blood samples taken from women and newborns between 1997 and 2001 enrolled in a study designed to examine risk factors for preeclampsia. This serious complication of pregnancy is marked by elevated blood pressure and edema (swelling) of the hands and feet, and is a leading cause of premature delivery and maternal and neonatal complications including death. The results of the study show that a maternal vitamin D deficiency early in pregnancy is a strong, independent risk factor for preeclampsia. This increase risk continued even after adjusting for other known risk factors such as race, ethnicity and pre-pregnancy body weight.

Another concern was the fact that many of the women were taking prenatal vitamins, which typically contain 200 to 400 IU of vitamin D. "Even a small decline in vitamin D concentration more than doubled the risk of preeclampsia," noted James M. Roberts, M.D., senior author of the study. "And since newborn's vitamin D stores are completely reliant on vitamin D from the mother, low vitamin levels also were observed in the umbilical cord blood of newborns from mothers with preeclampsia." The researchers concluded that maternal vitamin D deficiency may be an independent risk factor for preeclampsia and vitamin D supplementation in early pregnancy should be explored for preventing preeclampsia and promoting neonatal well-being.

About preeclampsia

Source: Maternal Vitamin D Deficiency Increases the Risk of Preeclampsia, Lisa M. Bodnar, Janet M. Catov, Hyagriv N. Simhan, Michael F. Holick, Robert W. Powers, and James M. Roberts, Journal of Clinical Endocrinology & Metabolism September 2007, Vol 92, No.9:3517-22

Friday, September 21, 2007

Vitamin D supplementation lowers fracture risk

Researchers have found that doses of 700 to 800 IU of vitamin D3 per day may reduce the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent.

The May 11 2005 issue of the Journal of the American Medical Association published the results of a meta-analysis of 12 clinical trials involving vitamin D supplementation in the prevention of fracture. The analysis concluded that supplementation with higher than the commonly recommended 400 international unit (IU) doses of vitamin D reduces the risk of hip and nonvertebral fractures in older individuals. The vitamin D studies included a total of 19,114 men and women aged 60 and older. The trials used the form of the vitamin known as cholecalciferol, or vitamin D3, which, according to studies cited in the current review, may be much more effective than the dietary form of the vitamin. The researchers found that doses of 700 to 800 IU of vitamin D3 per day reduced the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent. Studies that used 400 IU vitamin D3 or less found no significant benefit for either type of fracture. The role of additional calcium supplementation could not clearly be defined from the studies, but it appears that at least 700 milligrams calcium per day may also be necessary for nonvertebral fracture prevention.

Source: Fracture Prevention With Vitamin D Supplementation, Bischoff-Ferrari HA et al, JAMA 2005 May 11;293(18):2257-64.

Thursday, September 13, 2007

Supplemental vitamin D and calcium reduces risk of diabetes

The incidence of type-2 diabetes is lower among women who get adequate calcium and supplement with vitamin D. Researchers used data from the Nurses Health Study, which includes over 83,000 women, to study the relationship of calcium and vitamin D intake to type-2 diabetes.

After 20 years of follow-up, it was concluded that a combined daily intake of over 1,200 mg of calcium and more than 800 IU of vitamin D was associated with a 33 percent lower risk of type-2 diabetes. Interestingly, dietary vitamin D intake did not appear to provide any statistically significant benefit. But the women who supplemented with at least 400 IU of vitamin D had a 13% lower risk of diabetes when compared to those who took less than 100 IU per day. Both dietary and supplemental calcium resulted in decreased risk of type-2 diabetes, and those with overall intakes above 1,200 mg had a 21% lower risk than those who got less than 600 mg per day. Elevated intakes of calcium and vitamin D, especially from supplements, are significantly associated with lower incidence of type-2 diabetes.

Source: Vitamin D and Calcium Intake in Relation to Type 2 Diabetes in Women, Anastassios G. Pittas et al, Diabetes Care 29:650-656, 2006

My recommendation: Active Calcium