several studies have examined the influence of emotions on cognition, but common everyday situations also testify to the prevalence of this phenomenon. Indeed, who has never forgotten something important under the effect of acute stress, or hasn’t witnessed a menopausal relative complaining about becoming forgetful? The mechanisms and neural circuits involved in emotions and cognition are inextricably linked, and the maintenance of this delicate neurochemical balance is easily disrupted from exposure to stress. Stress triggers a cascade of hormone and neurotransmitter release throughout the brain, affecting our thoughts, decision-making process and behavior. Understanding the Impact of Stress Hans Selye (1907-1982),
The role that Vitamin B plays, from the time we are in the womb right through the ageing process, cannot be underestimated. Let’s explore the importance of this family of vitamins throughout our life cycle.
The Importance of Vitamin B during Pregnacy.
Nutritional deficiencies can lead to adverse outcomes in reproduction such as infertility and miscarriage. In pregnancy, a B12 deficiency can lead to complications in neonatal development, increasing the risk of preterm birth and lower birth weight1 Low levels of maternal red blood cell folate and high homocysteine values mid-pregnancy have also been found to be associated with reduced fetal growth.2
Vitamin B6 for Nausea.
Nausea and vomiting are common during early pregnancy. Studies have shown Pyridoxine (vitamin B6) reduces the severity of nausea and vomiting in pregnant women3 Study participants between 6 and 16 weeks’ gestation given 40 mg of pyridoxine twice daily had significant improvements in symptoms versus those given placebo. Interestingly, the anti-nausea effects of B6 were comparable to that of ginger.
B Vitamins and Mood and Hormone Regulation.
B Vitamins perform a variety of actions that relate directly to the production of neurotransmitters, hormones, and therefore, mood. Through their blood sugar regulating actions, they help reduce mood swings, improve sleep, and assist the liver in detoxifying estrogens.4 z Pyridoxine, in particular, is needed for the body to produce GABA, dopamine and, with niacin and inositol, serotonin.⁵ They regulate how we feel and how we process and respond to stress. There is a well-documented link between a deficiency of B vitamins and depression, anxiety and stress.
Vitamin B as Energy Booster.
B vitamins are well-known for their energy-boosting abilities. Thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6) and biotin (B7) all play important supportive roles in the energy-producing reactions performed when our body breaks down carbohydrates, fats and proteins.5 B vitamins serve as co-factors in breaking down our food and are critical to ensuring the body is producing energy efficiently for immediate use or storage. Without them we are often left feeling worn out, stressed and, in some cases of severe deficiency, we may experience neurological symptoms such as muscle weakness and numbness. Other B vitamins, such as folic acid (B9), cobalamin (B12,) along with B5 and B6, contribute to our red blood cell production.⁵ When we have healthy red blood cells, we are delivering oxygen efficiently, keeping our brain, muscles and nervous system happy.
B Vitamins and Heart Health.
Several B vitamins have been identified as important to our cardiovascular health. Elevated homocysteine levels also pose an increased risk of damage to our blood vessels, resulting in arterial hardening known as arteriosclerosis. Arteriosclerosis develops when cholesterol is deposited into the arterial wall, leading to the formation of plaques. It is thought to occur when an abnormal distribution of cholesterol is present, due to poor dietary habits or genetic predisposition.6 While many B vitamins help reduce these risks, niacin has been touted as one of the most effective interventions for the reduction of cholesterol. Its therapeutic effects are outlined in Table 1.
Up to 13% reduction
Up to 25% reduction
Up to 30 % reduction
Improvement of 15-35%
B Vitamins & Cognitive Decline
Lately, there are many questions as to whether or not B vitamins are useful in helping those experiencing cognitive decline or neurodegeneration. Several forms of B vitamins have shown to be protective for the brain and beneficial in repairing damaged nerves.9,10Methylcobalamin, the methylated form of B12, has been shown to be helpful after nerve injury by assisting in rebuilding myelin, which improves speed and delivery of signalling through the nerves.11 Another B vitamin that has been shown to be neuroprotective is Benfotiamine, a more fat-soluble form of thiamin that is shown to be absorbed up to 5 times more and is up to 3.6 times more bioavailable than thiamin hydrochloride. 12 Studies have suggested that Benfotiamine helps decrease symptoms of diabetic retina and nervous system damage caused by excess blood sugar which, if left unmanaged, can result in vision impairment and loss of sensation. 10 The brain consumes considerable energy to function. When available energy drops, cognition is affected.
Thiamine is essential to brain function, helping regulate the release and availability of energy to the brain. Disruption of this process is considered one of the most important precursors to cognitive impairment and progression of Alzheimer’s Disease (AD). This has led to the suggestion that TDP, a thiamine metabolite, be used as a biomarker for Alzheimer’s diagnosis, as those with AD have lower circulating levels of TDP.13 Benfotiamine has been studied in 5 subjects with mild-moderate Alzheimer’s disease for 18 months to see if correcting low levels improved cognition.14 Each participant who took 300 mg/day oral Benfotiamine over 18 months and showed cognitive improvements via mini-mental status examination.
Folate, Vitamin B12 and Alzheimer’s Disease.
One approach to studying cognitive decline has been to investigate non-genetic risk factors associated with the development of Alzheimer’s disease (AD). One such risk factor is high blood levels of the amino acid homocysteine. 15 When homocysteine is significantly elevated in our body, it results in physiological stress that can increase inflammation, as well as damage our cardiac and nervous systems. Folate and B12 are known to help remove homocysteine from the blood and, interestingly, these vitamins have been found to be low in individuals diagnosed with AD. In one study, a high-dose B vitamin treatment including folic acid, B6 and B12 slowed shrinkage of whole brain volume over two years compared to placebo. 16 It is important to note that not all cases of AD feature elevated homocysteine levels. Studies that have looked at the combination of folate, B6 and B12 have not been shown to slow cognitive decline in those with normal homocysteine levels.
Studies that have looked at the combination of folate, B6 and B12 have not been shown to slow cognitive decline in those with normal homocysteine levels. 15
Stronger when combined with Omega-3 Fatty Acids?
One retrospective study looked at the use of omega-3 fatty acids with B6, B12, and folate in elderly individuals over the age of 70 with mild cognitive impairment.17 Interestingly, B vitamin supplementation was only found to be beneficial in those with high baseline omega-3 levels, slowing brain atrophy by 40% compared with the placebo group. The researchers also acknowledged that AD patients with high homocysteine levels were less likely to respond to B vitamin intervention if the individual’s omega-3 fatty acid levels were low. It appears as though an individual’s use of omega-3 fatty acids before AD development may augment the effect of B vitamins in slowing cognitive decline and brain atrophy. Additional research with larger treatment groups is warranted to understand the lifestyle factors that may contribute to the progression of cognitive decline. While B vitamins may help slow decline, it is important to point out that the goal should be to reduce homocysteine levels earlier in life to control inflammation and reduce the risk factors that are within our control.
As we can see, the B family of vitamins are critical to the overall health of our hearts and minds – as well as the rest of our bodies – from before we are born and throughout our lives.
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2. Furness D, Fenech M, Dekker G, Khong T, Roberts C, Hague W. Folate, vitamin B12, vitamin B6 and homocysteine: impact on pregnancy outcome. Matern Child Nutr. 2013 Apr; 9(2): 155-66
3. Sharifzadeh F, Kashanian M, Koohpayehzadeh J, Rezaian F, Sheikhansari N, Eshraghi N. A comparison between the effects of ginger, pyridoxine (vitamin B6) and placebo for the treatment of the first trimester nausea and vomiting in pregnancy (NVP). J Matern Fetal Neonatal Med. 2018 Oct; 31(19): 2509-14
4. Greenblatt, J. (2011). The Breakthrough DepressionSolution. North Branch, Minnesota: SunriseRiver press.
5. Groff, J. L., & Gropper, S. S. (1999). The Water-Soluble Vitamins. In J. L. Groff, & S. S. Gropper, Advanced Nutrition and Human Metabolism (pp.245-303). Wadsworth Thomson Learning.
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7. Guilliams, T. G. (2018). Cardiometabolic riskmanagement: a functional and lifestyle approach. Stevens Point, WI: Point Institute.
8. Ito MK. Niacin Based Thearpy for Dyslipedimia: past evidence and future advances. Am J ManagCar. 2002 Sep; 8(12 Suppl): s315-s22
9. Prousky, J. (2012). Integrative Clinical Nutrition. Toronto: CCNM Press Inc.
10. Wu S, & Ren J. Benfotiamine alleviates diabetes-induced cerebral oxidative damage independent of advanced glycation end-product, tissue factor and TNF-a. Neurosci Lett. 2006 Feb 13; 394(2), 158-62
11. Nishimoto S, Tanaka H, Okamoto M, Okada K, Murase T, Yoshikawa, H. Methylcobalamin promotes the differentiation of schwann cells and remyelination in lysophosphatidylcholine-induced demyelination of the rat sciatic nerve. Front CellNeurosci. 2015 Aug 4; 9(298): 1-13
12. Xie F, Cheng Z, Li S, et al. Pharmacokinetic study of benfotiamine and the bioavailability asessement compared to thiamine hydrochloride. J ClinPharmacol. 2014 June;54(6): 688-95
13. Pan X, Fei G, Lu J, et al. Measurement of blood thiamine metabolites for Alzheimer’s disease diagnosis. EBioMedicine. 2015 Nov 26; 3: 155-162
14. Pan X, Chen Z, Fei G, et al. Long-Term Cognitvie improvement after benfotiamine administration in patients with Alzheimer’s disease. Neurosci Bull. 2016 Dec; 32(6): 591-6
15. Aisen PS, Schneider LS, Sano M, et al. High-dose B vitamin supplementation and cognitive decline in Alzheimer Disease a randomized control trial. JAMA. 2008 Oct 15; 300(15): 1774-1783
16. Douaud G, Refsum H, de Jager CA, et al. Preventing Alzheimer’s disease-related gray matter atrophy by B-vitamin treatment. PNAS. 2013 June 4; 110(23): 9523-8
17. Jerneren F, Elshorbagy AK, Oulhaj A, Smith SM, Refsum H, Smith AD. Brain atrophy in cognitively impaired elderly: the importance of long chain w-3 fatty acids and B vitamin status in a randomized controlled trial. Am J Clin Nutr. 2015 Jul; 102(1): 215-21