The UL for adults for folic acid from fortified food or supplements not including folate from food is set at 1, mcg a day. One of the advances that changed the way we look at vitamins was the discovery that too little folate is linked to birth defects of the spine spina bifida and brain anencephaly. Fifty years ago, no one knew what caused these birth defects, which occur when the early development of tissues that eventually become the spinal cord, the tissues surrounding it, or the brain goes awry.
More than 30 years ago, British researchers found that mothers of children with spina bifida had low vitamin levels.
Timing of folate is critical. For folate to be effective, it must be taken in the first few weeks after conception, often before a woman knows she is pregnant. That is why women of childbearing age are urged to take extra folic acid as a supplement. Food and Drug Administration now requires that folic acid be added to most enriched breads, flour, cornmeal, pastas, rice, and other grain products, along with the iron and other micronutrients that have been added for years.
In , a Boston pathologist investigated the deaths of two children from massive strokes. Both had inherited conditions that caused them to have extremely high levels of a protein breakdown product in their blood, and both had arteries as clogged with cholesterol as those of a year-old fast food addict. How do B vitamins fit into the homocysteine picture?
Folate and vitamin B12 play key roles in converting homocysteine into methionine, one of the 20 or so building blocks from which the body builds new proteins. Without enough folate, vitamin B6 , and vitamin B12 , this conversion process becomes inefficient and homocysteine levels increase.
On the flip side, homocysteine levels drop with increasing intakes of folate, vitamin B6, and vitamin B Since these early observations about homocysteine, most but not all studies have linked high levels of homocysteine with a modest increase in risk of heart disease and stroke. Ideally, this would be tested in randomized trials. Several large randomized trials of B vitamin supplements to lower homocysteine levels and prevent heart disease and stroke failed to find a benefit.
The studies found that taking high doses of the three B vitamins lowered homocysteine levels but did not lead to a reduction in coronary heart events. But looking at cardiovascular disease as a whole may have obscured a potential benefit of at least one of the B vitamins, and studying people who already have advanced vascular disease may be too late in the process.
One analysis of multiple studies suggests that folic acid supplements can reduce the risk of stroke in people who have not already suffered a stroke, but they do not reduce the risk of second stroke in people who have already had one. Trials that enrolled more men than women also showed more of a benefit, perhaps because men are at higher risk of stroke in general. Ultimately, folic acid supplementation may only reduce the risk of heart disease in people who have lower levels of folate intake, most likely in countries that do not fortify their food supply with folic acid.
In people who already get enough folate in their diets, further supplementation with high doses of folic acid supplements—much higher than what is found in a standard multivitamin—has not been found to be beneficial and might actually cause harm. Folate plays a key role in cell growth and building DNA, the complex molecule that forms our genetic blueprint. It is believed that folate may play a role in both suppressing some types of early cancer, as well as progressing established cancers if high doses of folic acid are used.
Observational studies show that people who get higher than average amounts of folate from their diets or folic acid supplements for 15 years or more have lower risks of colon cancer [25] and breast cancer. But the relationship between folate and cancer is a complicated one, especially for people at high risk of colon cancer. A multiyear trial looked at whether high-dose folic acid supplements could prevent new polyps in people who had a history of polyps.
Keep in mind that this study tested a high dose of folic acid, more than two times higher than what is found in a standard multivitamin; furthermore, study participants were already at a very high risk of developing new polyps.
This may be another case where timing of folate intake is critical. Getting adequate folate may prevent polyps in people who do not have them, but high dose folic acid supplements may speed up polyp growth in people who do. In the U. The steady decline in deaths from colon cancer before and after the onset of folic acid fortification suggests that screening, not folic acid fortification, is responsible for the uptick in colon cancer rates.
The overall evidence from studies in humans shows a lower risk of colon and breast cancer with greater intake of folate or folic acid, rather than increased risk. The study did not find a negative impact of the folate fortification program on cancer risk and even suggested a protective role.
When teasing out the relationship between any vitamin supplement and cancer, it is important to remember that cancer cells are essentially our own cells on overdrive, growing and rapidly dividing, and they have a greater need for nutrients than most of our normal cells do. Studies done decades ago show that folate is needed for tumor cell growth.
Indeed, one successful chemotherapy agent works as a folate antagonist, since rapidly dividing cells require folate to maintain their fast pace of cell division.
So for people who have cancer or precancerous growths, nutritional supplements may be a double-edged sword. If you have cancer, make sure to check with your doctor before beginning any vitamin supplement regimen. Some observational studies have found a link between low blood levels of folate and higher risk of dementia. However, clinical trials have not found that folic acid supplementation prevents the development of dementia or improves cognitive function even if it reduces homocysteine levels.
A wide variety of foods naturally contain folate, but the form that is added to foods and supplements, folic acid, is better absorbed. In January , the U. Food and Drug Administration required food manufacturers to add folic acid to foods commonly eaten, including breads, cereals, pasta, rice, and other grain products, to reduce the risk of neural tube defects.
The amounts added to these products can vary and might only be small. Because vitamin D is only found in a small number of foods, whether naturally or added, it is difficult to get enough from foods alone.
Do not take more than micrograms 4, IU of vitamin D a day as it could be harmful. You can get vitamin supplements containing vitamin D free of charge if you're pregnant or breastfeeding and qualify for the Healthy Start scheme. If you're still spending more time indoors than usual this spring and summer, you should take 10 micrograms IU of vitamin D a day to keep your bones and muscles healthy.
But there is currently not enough evidence to support taking vitamin D solely to prevent or treat coronavirus. You may need to consider taking a daily supplement of vitamin D all year. Talk to a midwife or doctor for advice. If you do not have enough iron, you'll probably get very tired and may suffer from anaemia.
If you'd like to eat peanuts or foods that contain peanuts such as peanut butter during pregnancy, you can do so as part of a healthy, balanced diet unless you're allergic to them or your health professional advises you not to. Many breakfast cereals have iron added to them. If the iron level in your blood becomes low, a GP or midwife will advise you to take iron supplements. It's found in a wide variety of fruit and vegetables, and a balanced diet can provide all the vitamin C you need.
A varied and balanced vegetarian diet should provide enough nutrients for you and your baby during pregnancy. Talk to a midwife or doctor about how to make sure you're getting enough of these important nutrients. If you're vegan or you follow a restricted diet because of a food intolerance for example, a gluten-free diet for coeliac disease or for religious reasons, talk to a midwife or GP.
Ask to be referred to a dietitian for advice on how to make sure you're getting all the nutrients you need for you and your baby. Find out more about healthy eating if you're pregnant and vegetarian or vegan.
You may be eligible for the Healthy Start scheme , which provides vouchers to buy milk and plain fresh and frozen fruit and vegetables at local shops. You can also get coupons that can be exchanged for free vitamins. Buy it now.
A powerful vegetarian health tablet the size of a small black bean that can protect your body against anemia and keep you energized. B vitamins have a direct impact on energy levels, and 1, mcg of folic acid is a strong does that enables your body to absorb nutrients from food and convert that food into energy. Buy it here.
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