Among the water-soluble vitamins, the closely linked B vitamins stand out for how they support energy and overall vitality. All of them play an important role in keeping the body working well. The most prominent members of this group are B2 (riboflavin) and B1 (thiamine). Professor G. Sherman, a longevity researcher, calls vitamin B2 essential for extending lifespan: “A deficiency of riboflavin in the body is quite common,” he says. “The effects manifest over a considerable period, ultimately shortening lifespan.”
Vitamin B2 participates in key biochemical reactions that promote growth and tissue repair. A deficiency sharply reduces the absorption of proteins and carbohydrates because riboflavin is part of the enzymes that enable their oxidation in cells. Lack of riboflavin can also cause digestive and nervous system disorders, chronic colitis and gastritis, general weakness, and various skin and eye problems. Aim for 2–3 mg of riboflavin daily to lower the risk of these issues.
You can find riboflavin in peas, beans, Brussels sprouts, cauliflower, spinach, and rose hips (rose hips contain more than many other plant sources: up to 0.4 mg per 100 g fresh and up to 0.7 mg per 100 g dried). Brewer’s yeast, liver, eggs, milk, and dairy products are also rich in vitamin B2. Keep in mind that riboflavin is very sensitive to light: milk stored in clear glass exposed to light loses a significant amount of riboflavin. It is also partially destroyed by prolonged heating.
An inseparable partner of riboflavin is vitamin B1 (thiamine). Thiamine is necessary for normal nervous system function, for maintaining stomach peristalsis, and for keeping gastric acid levels in balance. Insomnia, irritability, or digestive complaints—especially constipation—can be signs of insufficient vitamin B1. The daily requirement (about 2 mg) can be met with 300–400 g of whole-grain rye (black) bread. Bran, peas, beans, unrefined grains (barley, oats, buckwheat), liver, pork, and brewer’s yeast are also high in vitamin B1. Thiamine does not accumulate in the body, so include thiamine-containing foods in your diet every day. Like riboflavin, thiamine is destroyed by prolonged heating.
Vitamin B5 (pantothenic acid) is important for the health of the endocrine and nervous systems. A deficiency can cause metabolic problems such as dermatitis, loss of pigment, and stunted growth. The daily requirement for vitamin B5 is 10–20 mg. Good sources include yeast, liver, milk, egg yolk, peas, and beans.
Vitamin B6 (pyridoxine) helps the body absorb both plant and animal proteins as well as unsaturated fatty acids. Together with calcium, pyridoxine helps muscles function and relax properly. The typical need for vitamin B6 (2–3 mg) is usually met by foods like whole-grain bread, bran, peas, beans, liver, meat, yeast, eggs, and milk.
Vitamins B9 (folic acid) and B12 (cyanocobalamin) work together in amino acid synthesis, blood formation, and in regulating carbohydrate and fat metabolism. A deficiency can lead to anemia. The daily requirements for these vitamins are very small—measured in micrograms. The best sources of vitamin B9 are parsley leaves, legumes, and green onions; B9 is also present in bread and grain products.
Vitamin B12 is virtually absent from plant foods. Its main sources are animal products such as liver, kidneys, meat, eggs, and milk.
To help prevent a deficiency of B vitamins, add dry yeast to your first courses (about 2 tablespoons a day is sufficient). Include fermented dairy products—kefir, buttermilk, and yogurt—in your diet. In Western Europe and North America, where life expectancy tends to be higher, yogurt is often considered an important part of a healthy diet.
