Thursday, February 19, 2009
Low vitamin D levels lead to poor physical performance in the elderly
In addition to its role in bone health, vitamin D is thought to play a role in musculoskeletal function. In a recent study, researchers examined the association between vitamin D status and physical performance in a sample of 976 persons over the age of 65. The physical performance of the subjects was analyzed using a short physical performance battery (SPPB) and handgrip strength. The SPPB tests included walking speed, ability to stand from a seated position, and ability to maintain balance in progressively more challenging positions.
Over 28% of the women and 13% of the men had vitamin D levels low enough to be considered a deficiency. Nearly three-fourths of the women and over half of the men had vitamin D levels that were considered insufficient. Among subjects with low vitamin D levels, physical performance and grip strength were significantly lower than that of participants who did not have reduced levels. The finding remained valid after taking into consideration other factors (such as season of the year and physical activity levels).
Given the high prevalence of vitamin D deficiency in older populations, additional studies examining the association between vitamin D status and physical function are needed. Current vitamin D recommendations are based on its role in bone health, although emerging research indicates vitamin D may also play important roles in preservation of muscle strength and physical function, as well as potential preventative roles in conditions such as cancer.
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 62:440-446 (2007)
Sunday, February 15, 2009
Vitamin D insufficiency common among breast cancer survivors
Vitamin D influences pathways related to cancer development, but little is currently known about vitamin D status in breast cancer survivors. Recent data taken from the Health, Eating, Activity and Lifestyle (HEAL) study showed a correlation between vitamin D status and breast cancer survivors. Vitamin D concentrations from 790 female breast cancer survivors were obtained and vitamin D insufficiency was found in 597 individuals - or 75% of participants. Average vitamin D concentrations were even lower among African American and Hispanic women.
Controlling for various factors such as body mass index (BMI), race/ethnicity, geography, season, physical activity, diet, and cancer treatments showed that stage of disease independently predicted vitamin D levels. In this group of breast cancer survivors the prevalence of vitamin D insufficiency was abnormally high. Based on these results, health professionals and clinicians should consider monitoring vitamin D status in breast cancer patients in addition to administering appropriate cancer treatments.
American Journal of Clinical Nutrition, Vol. 88, No. 1, 133-139, July 2008
Friday, December 19, 2008
Multivitamins and Healthy Immune Function
Adequate nutrient intakes are required for the immune system to function efficiently. A good multivitamin can enhance the immune system by supporting the body's natural defenses on both a structural and cellular level.
A recent article published in the British Journal of Nutrition summarizes the roles of select vitamins and trace elements in immune function.
Adequate intakes of micronutrients are required for the immune system to function efficiently. Micronutrient deficiency suppresses immunity by affecting antibody responses, leading to imbalances in the immune system. This situation increases susceptibility to infections, which increases disease and death risk. In addition, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Inadequate intakes of micronutrients are common in people with eating disorders, smokers (active and passive), individuals with chronic alcohol abuse, certain diseases, during pregnancy and lactation, and in the elderly.
Micronutrients contribute to the body's natural defenses on three levels by supporting physical barriers (skin/mucosa), cellular immunity, and antibody production. Vitamins A, C, E, and the mineral zinc assist in enhancing the skin barrier function. Vitamins A, B6, B12, C, D, E, and folic acid, and the minerals iron, zinc, copper and selenium work synergistically to support the protective activities of the immune cells. Finally, all these micronutrients, with the exception of vitamin C and iron, are essential for the production of antibodies.
Overall, inadequate intake and status of these vitamins and minerals may lead to a suppressed immune system, which increases the risk of infections and aggravates malnutrition. Therefore, supplementation with a multivitamin that includes these micronutrients can support the body's natural defense system by enhancing all three levels of immunity.
Wednesday, December 17, 2008
New Guidelines Double Amount Of Recommended Vitamin D For Young / ScienceDaily (Oct. 14, 2008)
The previous recommendation, issued in 2003, called for 200 IU per day beginning in the first two months of life.
The change in recommendation comes after reviewing new clinical trials on vitamin D and the historical precedence of safely giving 400 IU per day to the pediatric population. Clinical data show that 400 units of vitamin D a day will not only prevent rickets, but treat it. This bone-softening disease is preventable with adequate vitamin D, but dietary sources of vitamin D are limited, and it is difficult to determine a safe amount of sunlight exposure to synthesize vitamin D in a given individual. Rickets continues to be reported in the United States in infants and adolescents. The greatest risk for rickets is in exclusively breastfed infants who are not supplemented with 400 IU of vitamin D a day.
Adequate vitamin D throughout childhood may reduce the risk of osteoporosis. In adults, new evidence suggests that vitamin D plays a role in the immune system and may help prevent infections, autoimmune diseases, cancer and diabetes.
"We are doubling the recommended amount of vitamin D children need each day because evidence has shown this could have life-long health benefits," said Frank Greer, MD, FAAP, chair of the AAP Committee on Nutrition and co-author of the report. “Supplementation is important because most children will not get enough vitamin D through diet alone.”
"Breastfeeding is the best source of nutrition for infants. However, because of vitamin D deficiencies in the maternal diet, which affect the vitamin D in a mother’s milk, it is important that breastfed infants receive supplements of vitamin D,” said Carol Wagner, MD, FAAP, member of the AAP Section on Breastfeeding Executive Committee and co-author of the report. “Until it is determined what the vitamin D requirements of the lactating mother-infant dyad are, we must ensure that the breastfeeding infant receives an adequate supply of vitamin D through a supplement of 400 IU per day.”
The new recommendations include:
Given the growing evidence that adequate vitamin D status during pregnancy is important for fetal development, the AAP also recommends that providers who care for pregnant women consider measuring vitamin D levels in this population.
Adapted from materials provided by American Academy of Pediatrics.
http://www.sciencedaily.com/releases/2008/10/081013141737.htm
Tuesday, August 26, 2008
Add the Sunshine "D" to Your Diet for Longer Life Expectancy
A new meta-analysis of 18 randomized controlled trials showed that individual who took vitamin D supplements had a 7% reduction in all-cause mortality. This meta-analysis covered 57311 participants, with 4777 deaths from all causes during size-adjusted mean of 5.7-years trial period. Daily doses of vitamin D supplements varied from 300 to 2000 IU with a mean daily vitamin D dose at 528 IU).
This study concluded that intake of ordinary doses of vitamin D supplements seems to be associated with decreases in total mortality rates. The relationship between baseline vitamin D status, dose of vitamin D supplements, and total mortality rates remains to be further investigated.
Article Source: Archives of Internal Medicine 2007; 167(16):1730-7.