Another study evaluated the efficacy of combined folic acid, vitamin B6, and vitamin B12 in reducing cancer risk among women. Their result reveal that combined folic acid, vitamin B6 and vitamin B12 treatment had no significant impact on overall risk of total invasive cancer or breast cancer among women through the folic acid fortification era.
A study published in December 2008 evaluated whether vitamins C and E and beta carotene supplementation make a splash on overall cancer risk. The information was extracted from the Women's Antioxidant Cardiovascular Study and involved 8,171 women have been cancer-free from the beginning of the research about 9.4 years ago. The findings of the study revealed that "supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality."
The Women's Health Initiative Calcium/Vitamin D Trial evaluated the consequences of vitamin D and supplements on blood pressure and risk for hypertension risk of 36,252 healthy postmenopausal women. The ladies were assigned in 2 groups: one group received a regular supplement of 1000 mg of calcium plus 400 IU of vitamin D3 daily. The other group received placebo only. The researchers reported that "in postmenopausal women, calcium plus vitamin D3 supplementation did not reduce either blood pressure or the risk of developing hypertension over 7 years of follow-up."
The Physicians'Health Study II evaluated whether vitamin E or vitamin C have cardioprotective properties that will reduce risk for CVD in men. A complete of 14,641 American doctors were enrolled in the analysis, aged 50 years and older, and were followed up for 8 years. The analysis results revealed that "neither vitamin E nor vitamin C supplementation reduced the risk of major cardiovascular events. These data provide no support for the use of these supplements for the prevention of cardiovascular disease in middle-aged and older men."
This study evaluated whether antioxidant (vitamins E, C and/or beta-carotene) supplements can prevent atherosclerosis. The researchers performed a meta-analysis of 22 trials which involved 134,590 participants. The researcher conclude that "...the most studies one of them review does not support a possible role of antioxidant supplementation in reducing the danger of cardiovascular disease ... no definite conclusion can be drawn to justify the utilization of antioxidant vitamin supplements for the prevention of atherosclerotic events."
Folic acid is routinely prescribed for expectant mothers to stop birth defects such as for instance spina bifida. It has been believed that folic acid, which reduced the levels of homocysteine in the blood, can prevent cardiovascular disease. Homocysteine is definitely an amino acid used as biomarker for cardiovascular disorder. This trial investigated whether a vitamin combination pill with folic acid, vitamin B6, and vitamin B12 (vs. a placebo) can reduce cardiovascular risk. It enrolled more than 5,400 American women with a history of cardiovascular disease or with moderate to high risk profile for ccardiovascular disease. After 7.3 years of treatment and follow-up, a mixture pill of folic acid, vitamin B6, and vitamin B12 didn't reduce a mixed end point of total cardiovascular events among high-risk women, despite significant homocysteine lowering.
While all the evidence from studies summarized here doesn't seem to guide medical great things about vitamin supplements, there are a few studies which indicate that vitamin D supplementation is worthwhile, even essential. Vitamin D is exclusive because we cannot get our vitamin D requirements from food alone. Instead, vitamin D is synthesized by the human body upon exposure of the skin to the sun, thus earning it the title "sun vitamin." However, since sunlight is said to cause skin cancer, people tend to avoid exposure resulting in widespread vitamin D deficiency.
American health experts are convinced of the necessity of vitamin D supplements and thus, routinely prescribe vitamin D supplements even for newborn babies. Milk and other dairy products in the US are fortified with vitamin D but not in many areas of the world. This past year, the American Academy of Pediatrics updated its guidelines for vitamin D supplementation to recommend the doubling of the dose for babies and children from 200 IU to 400 IU per day.