Lesson 15: B Vitamins

B Vitamins

Thiamin (Vitamin B1 )

  • Assists the release of energy from carbohydrates and protein
  • The Metabolism of amino acids
  • The functioning of the nervous system

Daily Intake Recommendations: Men: 1.2 mg
, Women: 1.1 mg Pregnancy: 1.4 mg Breast-feeding: 1.4 mg

Sources: Fortified Vegan Milks, peas, macadamia nuts, sunflower seeds, beans, lentils, cantaloupes, avocado, and carrot juice. Vitamin B1 is sensitive to heat and diminishes with cooking. For example 100g fresh carrot juice, provides 0.01 milligrams of vitamin B1, One tablespoon of dried spirulina provides 0.17 mg of vitamin B1, or thiamine , One bowl of porridge is 0.30mg of B1 and 100g of sunflower seeds is 1.48 mg of B1.

To ensure sufficient intake of B1. Ensure daily intake of oats, spirulina, and sunflower seeds ( other seeds such as flax)

Read More about B1 Here

Riboflavin (Vitamin B2)

This water-soluble B vitamin helps convert food to fuel, encourages iron absorption in the intestines, and also enhances the health of hair, skin, muscles, eyes, and the brain . And some research suggests that riboflavin may be effective at combating migraines, too . Riboflavin deficiency is uncommon, but is associated with a sore throat, cracks and sores around the lips, an inflamed “magenta tongue” , and scaly skin . While enormous intake of riboflavin may turn your pee bright yellow (a phenomenon called flavinuria), this side effect is harmless.

What You Need: Men = 1.3mg; Women = 1.1mg per day

Sources: Mushrooms, Almonds (0.23 mg per ounce) / roughly 5 oz of almonds (150g)

Niacin ( a.k.a. Vitamin B3 or Nicotinic Acid)

On the lookout for beautiful skin, hair, and red blood cells? Niacin is here to help! Like other water-soluble B vitamins, niacin is essential for converting food into energy. It’s also central for the health of skin, hair, eyes, liver, and the nervous system, and is believed to lower risks of high cholesterol and heart disease . Extreme deficiencies in niacin may lead to pellagra, which is associated with the “the four D’s”: dermatitis (skin irritation), diarrhea, dementia, and death . But don’t overdo it either: Pellagra is exceptionally rare. High doses of niacin can be toxic, and may cause rosy tingling — the so-called “niacin flush” — if doses exceed 50 mg per day .

What You Need: Men = 16 mg; Women = 14 mg per day

Sources: Almond butter 100g = 8mg, chia seed 80g = 13mg, sunflower cheese 250g sunflower seeds = 25.3mg, sundriend tomato 55g = 5.8mg.

Listen to B3 Niacin Expert Dr. Chris Masterjohn 

Pantothenic Acid (a.k.a. Vitamin B5)

This vitamin is important in food metabolism and helps synthesize neurotransmitters, steroid hormones, red blood cells, and more. Toxicity is virtually nonexistent, and while B5 deficiency is fairly rare (it tends to accompany severe malnutrition) neurologic symptoms such as burning feet.

What You Need: 5 mg (AI) per day

Sources:  Mushrooms (0.52 mg per half cup), sweet potato (0.88 mg per medium potato), avocados (1.99 mg per whole avocado).

Vitamin B6 (a.k.a. pyridoxal, pyridoxine, pyridoxamine)

This essential, water-soluble vitamin flies high above the others. Vitamin B6 helps out with the production of serotonin, a hormone that plays a hand in sleep, appetite, and mood . It also assists with manufacturing red blood cells and steroid hormones, influences cognitive and immune function, and is linked to reducing the risk of heart disease . Diets lacking B6 are rare, but evidence of seizures and other neurologic systems are observed in extreme deficiency. Adverse effects from high doses are primarily seen in people taking supplements, and include pain and numbness in the limbs .

What You Need: 1.3 mg per day

Sources: Bananas (0.43 mg per medium banana),  hazelnuts (0.18 mg per ounce), and cooked spinach (0.44 mg per cup).

Biotin (a.k.a. Vitamin B7 or Vitamin H)

Like the rest of the water-soluble B-complex vitamins, biotin plays a huge role in cell growth and food metabolism . Metabolism is the process by which our bodies covert the food we eat into energy that can then be used to power everything we do, from thinking, to running. Deficiency of this vitamin is extremely rare.

What You Need: 30 mcg per day

Sources: Avocados (2-6 mcg per avocado), 142g almonds = 97mcg, walnuts 125g = 23mcg, Nutritional Yeast tablespoon = 8mcg. cauliflower and raspberries are also good sources.

Folate (B9)

Folate and vitamin B12 were discovered as a result of a frantic search for a cure for megaloblastic anemia—a type of anemia that was particularly prevalent in the late 1870s and early 1880s. If the name folate sounds reminiscent of foliage, that’s because the vitamin was found in dark-green leafies. The term “folic” is from the Latin folium meaning leaf. While it was initially found in greens, it actually occurs in a variety of foods.The terms folic acid and folate are not interchangeable. Folic acid, the form in supplements and fortified foods, refers to the vitamin’s oxidized form. Folate, however, refers to the compounds reduced form that’s naturally present in foods and biological tissues.

Folate is made up of three parts, each of which has to be present for it to exert vitamin activity. In case you’re interested:

  1. Pteridine or pterin (2-amino-4-hydroxypteridine)
  2. Para-aminobenzoic acid (PABA)
  3. Glutamic acid—metabolically active folate actually has multiple glutamic acid residues attached. These would be referred to as pteroylpolyglutamates.

Humans can actually synthesize all of the above components, but we lack the conjugase enzyme needed to couple pterin to PABA to make pteroic acid. As with most vitamins, folate can take many forms in food. While there are a handful of variants commonly found in food, over 150 have been reported. The main pteroylpolyglutamates found in foods are 5-methyl tetrahydrofolate (THF) and 10-formyl THF—the forms that fulfill most metabolic roles. Pteroylpolyglutamate is also the form of folic acid provided in fortified foods and supplements.

Plant-Based Sources of Folate

  1. Greens. As for plant sources, folate is found most notably in dark green leafies like spinach, turnips, and collard greens. Spinach provides about 52.8 mcg or 15% DV per 1 cup.8
  2. Legumes. For example, pinto beans and black beans, lentils, lima beans, and kidney beans. Pinto beans (1/2 cup) provide 72 mcg or 18% DV.9
  3. Brussels sprouts. 1 cup provides 53.7 mcg or 13% DV.10
  4. Asparagus. 1 cup provides 69.7 mcg or 17% DV.11
  5. Broccoli. 1 cup, chopped, provides 57.3 mcg or 14% DV.12
  6. Okra. ½ cup provides 36.8 mcg or 9% DV.13
  7. Peanuts. 1 oz. provides 40.6 mcg or 10% DV.14
  8. Fruits. For example, strawberries, oranges, cantaloupe, and banana. 1 cup of strawberries provides 36.5 mcg or 9% DV.15
  9. Enriched bread. 1 large slice of commercially-prepared bread contains 33.3 mcg or 8% DV.


I mentioned above that folic acid is the form used in supplements and fortified foods. Often, synthetic nutrients are less effective than those found in whole foods (vitamin E, etc.). Well, folic acid is an exception, as it’s almost 100% bioavailable, especially if you consume it on an empty stomach.5

If consumed with natural sources of folate, the bioavailability of folic acid drops to about 85% which is still really good considering that folate bioavailability from a mixed diet is closer to 50%, on average, though it can vary from 10% to 98%.

Vitamin B12:

Another water-soluble B vitamin, vitamin B12 offers a helping hand in the metabolism of fatty acids and amino acids, cell creation, and the protection of nerve cells , and also may reduce the risk of Alzheimer’s . Keep B12 close when it gets to those later, grey-haired years: deficiencies are common in the elderly and may cause memory loss, dementia, and anemia . Toxicities are not observed, and vegetarians and vegans do need to supplement with B12. B12 also protects the nervous system and without it permanent damage can result (e.g., blindness, deafness, dementia). Fatigue and tingling in the hands or feet are often the early signs.

Vitamin B12, like folate (aka folic acid), is needed to help red blood cells divide. In some cases, vegans may get so much folate that even with B12 deficiency, their blood cells continue to divide properly. But in other cases, a vitamin B12-deficient vegans’ blood cells will fail to divide properly and they’ll become fatigued due to macrocytic anemia, also known as aka megaloblastic anemia anemia.

What You Need: 2.4 mcg per day – 10mcg per day ( to ensure optimum absorption). B12 Methylamonic Acid test can test for proper B12 absorption which can be impaired if there is a lack of the protein called intrinsic factor which converts b12 to its useable form in the stomach. Intrinic factor protein can be impacted by autoimmune disease. Another test can be a Homocysteine test as homocysteine is a byproduct of protein metabolism that the body clears with the help of vitamin B12. Elevated homocysteine is a sign of B12 deficiency and high levels of homocysteine are linked with increased risks of dementia, heart disease, and stroke.

Active and Inactive Analogues

Vitamin B12 is a coenzyme: it is needed for enzymes to do their job of changing one molecule into another. As vitamins go, B12 is large. One part of its structure is known as the corrin nucleus, which holds an atom of cobalt. The corrin resembles the heme of hemoglobin which holds an atom of iron. Any molecule that contains a corrin nucleus is considered a corrinoid. The corrin plus other atoms make up the cobalamin part of B12. There are many different cobalamins and they are named after their attachments. For example, methylcobalamin is cobalamin with a methyl group (one carbon and three hydrogens) attached. Only two cobalamins are active as coenzymes in the human body: adenosylcobalamin and methylcobalamin. The body has the ability to convert at least some other cobalamins into one of these active forms.

Cyanocobalamin (a cyanide molecule attached to a cobalamin) is the form most often found in supplements and fortified foods because it is the most stable form of B12. The cyanide in cyanocobalamin is in amounts small enough not to be harmful to anyone except possibly those with cyanide metabolism defects.

Most people readily convert cyanocobalamin into one of the B12 coenzymes. Hydroxocobalamin is also common in foods and the body; it can be converted into a B12 coenzyme. There is a complex process and best to get tested regularly and ensure correct supplementation.

There are basically three B12 analogue transport proteins:

  • Intrinsic Factor – Facilitates uptake of B12 analogues into the intestinal cells in the ileum. Has a low affinity for many inactive analogues.
  • Transcobalamin – Facilitates uptake of B12 analogues into all cells in the body. Has a low affinity for many inactive analogues.
  • Haptocorrin – Facilitates uptake of B12 analogues into the liver cells. Has a high affinity for many inactive analogues.

Haptocorrin delivers B12 analogues to the liver where the inactive analogues are excreted in the urine and feces. Active B12 is released back into the blood, where it is taken to cells by transcobalamin.

Sources: Suppliment, Nutritional yeast

Listen to B12 Expert on podcast here Dr.Peter Osborne

Read More about B12 Science here