Just one-fifth of a milligram (mg) of folic acid, also known as vitamin B9, appears to be enough to effectively lower the body's level of homocysteine, according to the report published in the American Journal of Clinical Nutrition (AJCN).

Previous studies suggested that between 0.2 mg and 5 mg of folic acid administered each day could reduce homocysteine levels and potentially improve heart health.

The study in the AJCN found that doses of the vitamin higher than one-fifth mg may not eliminate any more of the amino acid.

Other researchers have suggested that reducing homocysteine levels may reduce the likelihood of heart attack and stroke.

In addition to helping the body process homocysteine, folic acid has a number of other health benefits, including reducing the risk of cancer in older adults and providing women who are pregnant with valuable nutrition for their growing babies.

Over the course of seven years, blood samples were taken from a total of 271 individuals aged 65 to 79 years who showed no signs of memory complications at the start of the study.

The researchers monitored the levels of homocysteine, an amino acid that is linked to vitamin B12, and holotranscobalamin, an active nutrient found in the vitamin, in each sample. The team followed the concentration of this amino acid because unhealthy levels can lead to brain complications and stroke.

The results showed that unhealthy levels of homocysteine increased one's risk of Alzheimer's disease by 16 percent, but also found the active form of vitamin B12 slowed the brain's aging process by 2 percent.

According to researchers, these findings "show the need for further research on the role of vitamin B12 as a marker for identifying people who are at increased risk of Alzheimer's disease." They added that "low levels of vitamin B12 are surprisingly common in the elderly, however, the few studies that have investigated the usefulness of vitamin B12 supplements to reduce the risk of memory loss have had mixed results."

Individuals who are interested in increasing their vitamin B12 intake can benefit from eating eggs, fish, poultry and shellfish. 

A lack of of omega-3 fatty acids and vitamin B12 was was found to have a particularly close association with the risk of atherosclerosis, according to a metastudy published in the Journal of Agricultural and Food Chemistry.

The authors qualified this statement by saying that meat eaters have a much higher total risk of heart disease, but that the above lack of nutrients still carries a moderate risk.

Researchers analyzed data from 30 years' worth of articles on the nutritive health of vegetarians. They discovered that vegetarians who abstain from all animal-derived products, including milk, cheese and eggs, tended to have low levels of iron, zinc, omega-3s and vitamin B12.

While the human body can extract iron and zinc from fresh fruits, vegetables and whole grains, the latter two nutrients are found almost exclusively in meat, seafood and eggs. Omega-3 and vitamin B12 deficiencies can predispose an individual to arterial hardening and blood clots.

The study's authors concluded that vegans and strict vegetarians may consider taking vitamin supplements that contain these nutrients, such as those derived from fish oil or nuts.

A study published in the journal Anesthesia and Analgesia found that hospital patients treated with nitrous oxide were 60 percent more likely to have a heart attack over the following three years.

Researchers theorized that this effect may be due to laughing gas's connection to homocysteine, an amino acid linked to the increased risk of heart disease.

Nearly 50 percent of the study's participants who were given nitrous oxide later displayed high levels of homocysteine in their blood.

While the team did not recommend discontinuing the use of nitrous oxide, it did note that the gas has previously been associated with a higher likelihood of infection and pneumonia.

The study's authors concluded that more research should be conducted into nitrous oxide's possible role in the advent of heart disease.

Currently, laughing gas is primarily used in dental procedures.

Healthcare professionals recommend folate supplementation for a variety of reasons, including the production of healthy new cells in the body, the prevention of certain cancers and the healthy development of babies in utero.

Studies have shown that adults over the age of 50 are at a 40 percent higher risk of hearing loss when they test positive for folate deficiency.

Consuming 400 micrograms of the vitamin each day may help mitigate hearing loss an maintain overall health.

The Bee added that folate helps the body break down the amino acid homocysteine, which is often present in the blood in high concentrations among those at the greatest risk of heart disease.

The National Institutes of Health (NIH) recommend that pregnant women be especially vigilant about consuming 400 micrograms of the nutrient daily, since vitamin B9 helps a growing fetus produce healthy new cells and reduces the severity of pregnancy-related anemia.

Besides fortified cereals, which tend to contain a full day's worth of folate per serving, good sources of the vitamin include beef liver, spinach, asparagus and other green vegetables, the NIH's Office of Dietary Supplements reports.

Called a satsuma, the fruit looks similar to a mandarin orange but has thinner, more leathery skin. It tastes similar to an orange but is reportedly easier to peel. Underneath its skin, the satsuma contains loads of vitamins.

One satsuma provides roughly half a person's recommended daily allowance of vitamin C, according to the UK Daily Mirror.

Studies have indicated that vitamin C supplementation may help lower cholesterol and improve heart and immune health.

The satsuma is also full of fiber, potassium and calcium.

The newspaper added that the fruit contains folate, or vitamin B9, which researchers have suggested may lower levels of the amino acid homocysteine. Excess homocysteine in the blood may indicate an increased risk for heart disease.

The American Heart Association reports that folate can help the body break down homocysteine. It suggests taking daily supplements that contain vitamins B6, B9 and B12, which are nutrients likewise found in satsumas.

In a clinical trial, scientists discovered that large amounts of vitamins B6, B12 and folic acid appeared to slow cerebral shrinkage and MCI, both of which are known to contribute to dementia.

Gustavo Roman, the director of the Alzheimer and Dementia Center at the Methodist Neurological Institute in Houston, Texas, said that patients who had high blood levels of homocysteine responded particularly well to the treatment.

Previous studies have associated excess homocysteine in the body with the onset of Alzheimer's disease.

While clinicians warned that the vitamin therapy may not work for all mature adults, they remained confident that further research into vitamin B's role in delaying dementia may result in more effective treatments for Alzheimer's.

In the U.S., 5.3 million people have Alzheimer's disease, according to the Alzheimer's Association.

Published in the journal Neurology, the study involved taking blood samples from mature adults over the age of 65 and analyzing them for their homocysteine content.

Homocysteine is an amino acid whose production is linked to vitamin B12. Too much homocysteine in the blood can indicate a vitamin B12 deficiency.

The amino acid's excess presence has also been linked to the increased risk for developing Alzheimer's disease, which is an irreversible degenerative brain condition.

The study's authors found that one micromolar increase in the amount of B12 in the blood decreased the risk of the condition by 16 percent.

They concluded that B12 is likely vital for preserving memory and neural health.

Individuals who take vitamin supplements may notice improvements in health and wellbeing, since the vitamin is vital to the body's cellular functions.

Individuals should consume 4 micrograms of vitamin B12 each day, according to the U.S. Department of Agriculture.

During the recent trial, patients enrolled had been diagnosed with mild cognitive impairment (MCI), which can lead to developing Alzheimer's diseases or other forms of dementia. Over the course of two years, participants were given oral supplements and injections containing different types of vitamin B—folic acid, B6 and B12.

The results showed that those who had already developed memory problems and had levels of the amino acid homocysteine benefited the most from increasing their intake of these nutrients. Furthermore, the researchers discovered that the group responded better to the injections than the supplements.

Gustavo C. Román, lead author of the study, stated that "I'm not saying that everyone who takes B vitamins will prevent dementia." He added that "but in the right dosage and for the appropriate patients, the vitamin B-12 treatment could be a step toward modifying disease progression."

Individuals who are looking for another natural alternative to improve their cognitive function can benefit from walking five to six miles per week, according to a study conducted at the University of Pittsburgh.
 

During a study, a team of researchers surveyed more than 58,500 people aged 40 to 70 years about their eating habits, and examined the collected information. After 14 years of follow-ups, the investigators found that more than 900 of the participants had died from strokes, a total of 424 from heart disease and 2,087 had passed away because of other heart-related diseases.

The investigators then took data from the questionnaires and divided the individuals into five groups based on their variance of vitamin intake that including folate, vitamin B-6 and B-12.

The results showed that women with the highest intake of folate and B-6 were less likely to suffer from strokes, heart disease and other cardiovascular illnesses as opposed to female participants with lower intake of these B vitamins. Also, the team found that men who consumed foods with high levels of folate and B-6 had a lower risk of dying from heart failure.

In 2006, approximately 81.1 million people in the U.S. were diagnosed with at least one type of cardiovascular disease, including a total of 6.4 million suffering from strokes, according to the American Heart Association.