Biological effects of folate/cobalamin imbalance in mammals

叶酸是一种制造DNA所需的维生素，也是所有细胞生长和分裂所必需的。叶酸需要另一种维生素--钴胺(维生素B12)才能正常发挥作用。叶酸(人造叶酸)经常被添加到动物饲料中。在加拿大和其他一些国家，叶酸也被添加到人类食物中，以帮助预防出生缺陷，如脊柱裂。然而，增加饮食中的叶酸含量而不增加钴胺可能会导致这些维生素的失衡。我们的长期目标是研究叶酸和钴胺失衡的生物学效应。我们假设，高叶酸/低钴胺饮食将改变基因(DNA)的表达方式，潜在地导致生物学问题。为了测试这一点，我们将在成年小鼠身上确定高叶酸/低钴胺饮食是否会改变基因的表达方式，以及这是否会导致血管功能问题。我们还将研究让怀孕小鼠摄入高叶酸/低钴胺饮食是否会导致基因表达的变化，增加脂肪，并削弱其后代处理葡萄糖的能力。我们的研究将有助于确定饮食中叶酸和钴胺的最佳比例。它还将提供证据，证明增加添加到强化食品中的叶酸量的安全性，以及可能需要添加钴胺。

Folate is a vitamin required to make DNA and needed by all cells for growth and cell division. Folate requires another vitamin, cobalamin (vitamin B12), to function properly. Folic acid (man-made folate) is often added to animal feeds. In Canada and some other countries folic acid is also added to human foods to help prevent birth defects such as spina bifida. However, increasing folic acid content of the diet without increasing cobalamin may cause an imbalance in these vitamins. Our long-term goal is to study the biological effects of folate and cobalamin imbalance. We hypothesize that high folic acid / low cobalamin diets will change how genes (DNA) are expressed potentially leading to biological problems. To test this, we will determine in adult mice whether a high folic acid / low cobalamin diet alters how genes are expressed and whether this leads to problems in blood vessel function. We will also study whether exposing pregnant mice to a high folic acid / low cobalamin diet leads to changes in gene expression, increased fatness and impaired ability to process glucose in their offspring. Our research will help determine the best ratio of folic acid to cobalamin in the diet. It will also provide evidence as to the safety of increasing the amount of folic acid added to fortified foods and the possible need to add cobalamin.