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Fully Active B Complex Fully Active B Complex 30 caps.
Doctor's Best
14.28 $
Location: eu

Fully Active B Complex 30 caps.

From 3 units only: 13.99 $ / Units. -2%

Shipping weight: 100g
No gluten
14.28 $ With VAT
0.48 $ / serving
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  • Bioactive formula of vitamins B
  • Contains folate of a new 5-MTHF generation
  • Vitamin B12 in a methyl form
  • Dual forms of active vitamins
  • Prevents disorders of methylation
  • Protects from hyperhomocysteinemia
  • Participates in energy metabolism
  • Supports the nervous system functions
  • Supports the maintenance of mental capacity
  • Contributes to the proper blood production
  • Supports the natural immunological processes
  • Participates in the processes of cell division
  • Maintains the proper state of the mucous membranes
  • Helps to keep healthy skin
  • Reduces tiredness and fatigue

Doctor's Best Best B Complex is a valued dietary supplement which contains a wide range of B vitamins and vitamin C. In comparison to similar preparations on the market, the product is distinguished by the contents of the biologically active forms of vitamins: B12 in a form of methylcobalamin, folate in a form of 5-methyltetrahydrofolate (5-MTHF) and vitamin B6 as pyridoxal phosphate. To achieve even greater effectiveness of the supplement, riboflavin (B2), niacin (B3) and vitamin B6 were used as a composition of two different forms of these vitamins.

Energetic metabolism
Numerous enzymes and pathways which are involved in the energy metabolism require, for their proper action, the participation of more than one vitamin from the B-group. For instance, two key enzymes of the Krebs cycle (the process of metabolic transformations which leads to the energy production) – pyruvate dehydrogenase and ketoglutarate dehydrogenase – need vitamins B1, B2, B3 and B5 to act properly. Moreover, mitochondria, which produce over 90% of the total energy of the body system, need all the B vitamins for the smooth functioning of most processes.

The transfer of methyl groups
Methionine synthase – an enzyme which transform homocysteine into methionine – requires active forms of vitamin B9 and B12 for the proper functioning. Hyperhomocysteinemia, which can result from the deficiency of both of these vitamins, is considered to be an independent risk factor of cardiovascular diseases, neurodegenerative disorders, fetal malformations and tumours.

Vitamin C (as ascorbic acid) is a vitamin which is necessary for the proper functioning of living organisms. It takes part in the transformation of tyrosine and the synthesis of adrenal steroids and collagen. Its level regulates the number of lymphocytes in the bloodstream, on which the immune system function is based. Furthermore, it shows protective properties against numerous toxic substances, such us: lead, carbon disulphide, aniline and others. What is more, it shows wide antioxidant properties and is able to protects DNA, proteins and fats from oxidation. It is necessary for the proper conduction of the phagocytosis processes.

Vitamin B1 (as thiamine hydrochloride) plays an essential role in the process of the energy production during aerobic transformations which take place in the mitochondria. It participates in the metabolism of amino acids, but its the most important role is the participation in the carbohydrates transformation. In the case of a diet rich in simple sugars, the reserves of vitamin B1 may be reduced.

The tissues which require large energy expenditure (nervous system, muscles, the heart muscle, the liver) have a fairly high demand for thiamine. This is why by the deficiency of this vitamin occur the disorders of their functions. Vitamin B1 has an especially important role in the activities and the regeneration of the central nervous system. It also supports the growth process and accelerates the wound healing as well as shows pain-killing properties.

Vitamin B2 (as riboflavin and riboflavin-5′-phosphate) plays an important role in energy metabolism by an active participation in the transformation of amino acids, lipids and carbohydrates and due to the fact that it is a cofactor for many mitochondrial enzymes. It is believed that up to 4% of all known enzymes in the human body system can use riboflavin or its metabolites in the processes of energy transfer. Riboflavin is contained in two coenzymes: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Thanks to that it participates in the processes of oxidation and reduction.

It plays a role in the proper functioning of the nervous system, and along with vitamin A, in the normal functioning of mucous membranes, respiratory tract, gastrointestinal mucosa, blood vessels epithelium and skin. Moreover, it contributes to the proper functioning of the sight organ. There are scientific evidences which indicate that riboflavin participates in the generation of red blood cells and the blood itself.

Vitamin B3 (as niacin and nicotinamide) participates in the transformation of energy components which should release energy. It participates in the generation of red blood cells, reduces the toxic action of chemicals and medicines, regulates the cholesterol levels in the bloodstream, dilates blood vessels, positively influences the nervous system and mental condition as well as it improves blood circulation in the skin and hair condition.

Vitamin B6 (as pyridoxine hydrochloride and pyridoxal 5'-phosphate / P-5-P) improves the immunity of the body system and participates in the generation of antibodies. It helps in the transformation of tryptophan into vitamin PP, which increases the level of the vitamin B6 in the body. It is also essential for the synthesis of porphyrins (the synthesis of heme to hemoglobine in the red blood cell production) and hormones (for example: histamine,    and serotonin).

The biologically active forms of vitamin B6 (coenzymes) are phosphate derivatives of pyridoxamine and pyridoxal. Enzymes with such coenzymes are involved mainly in transformation of amino acids, for instance in the racemisation of the optically active amino acids and the decarboxylation of amino acids. Pyridoxal phosphate cooperates with glycogen phosphorylase and participates in the transamination reaction.

Folic acid (as 5-methyltetrahydrofolate / 5-MTHF) participates in the formation of the nucleic acids – DNA and RNA, synthesis of amino acids and the process of cell division. It plays an important role in the process of red blood cells generation (together with vitamin B12), in the formation process of the myelin sheath of neurons and the conversion of homocysteine in methionine. Its deficiency during pregnancy may lead to the defects of neural tube and miscarriage, and in the adulthood – anemia excavatum.

Why folates instead of folic acid?
Levomefolic acid, 5-methyltetrahydrofolate (5-MTHF) is a folate – an active form of vitamin B9. Unlike folates, the folic acid can be transformed into its active form by the liver and not in the digestive system, which is less efficient and slower. The body system needs more time for the synthesis of 5-MTHF and this may disturb the general metabolism of the substance. It often results in the fact that folic acid will be deposited in the body system, which may increase the risk of particular tumours and may lead to latent deficiency of vitamin B12.

Vitamin B12 (as methylcobalamin) is required for the proper functioning of the nervous system and the gastrointestinal tract. The deficits of vitamin B12 can cause inhibition of growth and reproduction of cells (including red blood cells – erythrocytes), as well as degenerative changes of the spinal cord and the peripheral nerves in the central nervous system. The vitamin B12 deficiency leads also to megaloblastic anaemia.

Methylcobalamin is the most effective, best absorbable and biologically active form of vitamin B12. It is the only one to cross the blood-brain barrier and thanks to that it has an influence on the functioning of the central nervous system. Thanks to methyl groups, it stimulates the production of particular neurotransmitters. Moreover, it is of great importance in the process of growth and cell replication.

Among some people, the liver cannot convert cyanocobalamin, a common supplementary form of vitamin B12, into appropriate amount of methylcobalamin, which is essential for the proper functioning of neurons or to direct protection of brain cells from dangerous toxins.

Methylcobalamin achieves its neuroprotective effect by increasing methylation, accelerating the growth of nerve cells or the ability to neutralize the high homocysteine levels, which is responsible for the cardiovascular system diseases, atherosclerotic and thrombotic lesion, heart attack or stroke.

Biotin is built into the molecular structure of several enzymes (which are called carboxylases) which are the enzymes required in numerous important biochemical reactions, for instance in the process of glucose generation (gluconeogenesis), fatty acid synthesis, metabolism of branched amino acids or the citric acid cycle.

Biotin is also a vitamin which helps in the regulation of DNA structures and stabilisation of gene activity, and this mainly thanks to binding with proteins which are closely related to DNA. The researchers have identified more than 2,000 human genes which are dependent on biotin.

Pantothenic acid (as calcium pantothenate) is a component of coenzyme A as well as of the multienzyme complex which catalyses the synthesis of fatty acids. It participates in the synthesis of heme into hemoglobine and cytochromes. It takes part in the regeneration of skin cells and mucous membranes, participates in the generation of antibodies and supports the process of hair pigmentation.

To sum it all up, Doctor's Best Best B Complex is an excellent product which provides a wide range of B vitamins and vitamin C. It is recommended for people who are exposed to vitamin deficiencies which result from the disorders of nutrient absorption by the intestines and irregularities in the composition of the intestinal flora of the digestive system.

People who use elimination or one-component diets and elderly people are especially exposed to the deficits of B vitamins. The product may be very helpful in the supplementation of physically active people and athletes, who are exposed to loss of water-soluble vitamins as they are excreted with sweat. 

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Container size: 30 capsulesServing size: 1 capsuleServings per container: 30
per 1 capsuleamount%DV
Vitamin C (as ascorbic acid)40 mg45%
Vitamin B1 (from thiamin HCl)60 mg5000%
Vitamin B2 (from riboflavin and riboflavin-5-phosphate)75 mg5770%
Vitamin B3 (as niacinamide and niacin)50 mg310%
Vitamin B6 (from pyridoxine hydrochloride and pyridoxal-5-phosphate)50 mg2940%
Folate (from Quatrefolic®, (6S)-5-methyltetrahydrofolic acid, glucosamine salt)400 mcg100%
Vitamin B12 (as methylcobalamin)1000 mcg41670%
Biotin600 mcg2000%
Pantothenic acid (from d-calcium pantothenate)100 mg2000%

Other ingrednients

Modified cellulose (vegetarian capsule), magnesium stearate (vegetable source), microcrystalline cellulose, silicon dioxide, ascorbyl palmitate.

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Best to combine with

Vitamin C


Vitamin C (ascorbic acid) it is a vitamin soluble in body fluids, can be taken from foods (fruits and vegetables), or as drug derived synthetically. The largest of its resources can be found in broccoli, Brussels sprout, kale, black currant fruit and hawthorn, citrus fruits, tomatoes, Savoy cabbage, potatoes. In fact, intake of vitamin C of the food products does not limit the absorbed quantity. Vitamin C (ascorbic acid) is a potent antioxidant, it is an antitoxic, increasing the immune system due to the elimination of risk of bacterial contamination. Vitamin C prevents rupture of blood vessels, affects the blood cholesterol level. It substantially increases the absorption of iron. Inhibits the growth of cancer cells. Lowers stress levels.
Vitamin C deficiency causes abnormal development of connective tissue, cracking capillaries, abnormal calcification of bone tissue, impaired
absorption of iron, scorbutus. With the lack of vitamin C, all kinds of injuries do not heal up properly. Vitamin C deficiency can be caused by smoking; each cigarette is destroying up to 100 mg of vitamin C.
Dosage: The demand is 60-80 mg daily. It does not limit the ability to consume higher doses. Some side effects may occur only with longer
taking of synthetic vitamin C.

Ascorbic acid


Ascorbic acid – vitamin C. Its biologically active form is the L-isomer, which negatively rotates the polarised light, so that it is a dextroisomer (laevorotatory vitamin C does not exist). It is a strong antioxidant; it reduces the amounts of free radicals, which reduces oxidative stress, a factor leading to cell apoptosis, which is why it is indicated to be a cause for premature ageing.

It supports the immune system functions and increases body system immunity. It is an essential element of the collagen synthesis path, which is why it positively affects the condition of connective tissue. Hence, it promotes also wound healing and increases the durability of capillary vessel. It is involved in transformations of tyrosine and carnitine as well as of some nutrients, so that it affects metabolism. It can also have an impact on the nervous system functions, as it reduces mental fatigue.

Higher supply of vitamin C is especially recommended in the periods of more intensive body system burden, after infections and in order to accelerate regeneration. The indications for increased supply of the vitamin are also hard physical work or intensive trainings.

Vitamin B3


Vitamin B3 (vitamin PP, niacin, nicotinic acid, nicotinamide) is niacinamide niacin. It is used in interaction with vitamins B1, B2 and B6 in the synthesis of hormones during lactation. It provides proper functioning of the brain and nervous system. It is helpful in inflammatory conditions of the skin. Required for synthesis of sex hormone, estrogen, testosterone, cortisone, and insulin. It does not lose its properties in the manufacturing and storage. The source of acquiring vitamins PP are both products of animal origin (the lean meat, eggs, fish) and vegetable origin (dates, figs, hazelnuts, plums).
Dosage: 2-12 mg / day for children, 14 mg / day for women, 16 mg / day for men and 17-18 mg / day for pregnant or nursing women.


Vitamin B6


Vitamin B6 (pyridoxine, pyridoxal, pyridoxamine) is soluble in the liquid. It participates in the metabolism of proteins, fats and carbohydrates. By reducing the amount of fat in the blood do not enable deposition of the body. It helps the absorption of magnesium and vitamin B12 (cobalamin). It works on the muscle antispasmodic and anti-inflammatory pain in the joints. It acts anti. It provides efficient operation of the brain. It increases energy increasing vigor of a man. The demand for vitamin B6 increases during pregnancy and breast-feeding infants. The natural product is: yeast, eggs, wheat germ, meat (liver), wheat bran, nuts, peanuts peanuts, soybeans. There is a hypothesis that can be synthesized by intestinal bacteria.
Deficiency of vitamin B6 causes abnormal metabolism of proteins, decrease in lymphocytes in the blood, causes a feeling of lethargy and fatigue intensifies.
Dosage: 1.5-2.5 mg daily (increased demand during pregnancy and lactation).


Pyridoxine hydrochloride


What is pyridoxine hydrochloride?

Pyridoxine hydrochloride is a basic, the most commonly used form of vitamin B6 in supplements and fortified foods. It is a vitamin soluble in water. It converts to the active form of the vitamin - pyridoxal phosphate.

Vitamin B6 is a cofactor in many enzymatic reactions. It takes part in the production of many neurotransmitters, such as GABA, serotonin and catecholamines and it takes part in the metabolism of amino acids, carbohydrates and lipids. It is an important factor for the process of the creation of red cells and hemoglobin and its deficit may be one of the factors causing anemia. This vitamin contributes to maintaining proper energy metabolism and is important for maintaining well-being and good psychological condition. Its presence supports the breakdown of pro-inflammatory homocysteine to cysteine and further metabolites, thanks to which it may decrease the risk of atherosclerosis and cardiological incidents.

Pyridoxine hydrochloride may be found in many vitamin B complexes and vitamin-mineral preparations available in the offer of



Chlorine (chemical element from the group of halogens) - in the natural form of gas it is poisonous and water-soluble (until recently used as a disinfectant in the water supply system, now replaced by fluorination). It is chemically active element. It is used in the form of sodium chloride (NaCl) and potassium (KCl). It participates in the process of digestion and maintains acid-base balance in the body, removes toxic products of metabolism in the liver (antitoxin). Natural source of chlorine for the body is salt and bladderwrack.
Chlorine deficiency can occur due to excessive sweating, vomiting, causing digestive tract problems. It also causes loss of hair and teeth.
Excess chlorine, for example. Drink excessive amounts of chlorinated water, destroys bacterial flora and vitamin E.
Dosage: Daily dose should not exceed 15 grams.




Quatrefolic is the glucosamine salt of (6S)-5-methyltetrahydrofolate and also an active form of folic acid. It is an innovative nutrient (fourth generation folate) which is well soluble in water and thus absorbed effectively by the body. As an organic compound ranked among B vitamins, it is necessary for normal functioning at the cellular level.

Adding folates to a diet is recommended especially to pregnant and lactating women. These compounds may contribute to healthy foetal development. According to studies, their intake may reduce the incidence of pregnancy complications.

Some sources report that folate supplementation supports cardiovascular function (blood production) and contribute to healthy immune function.

Quatrefolic may affect the metabolism of homocysteine whose levels increase in the body over time. Adding it to a diet may thus prevent the development of dementia and maintain healthy cognitive functions which is vital to adults, especially the elderly.



Salt (sodium chloride, or table salt), natural source of electrolytes (chlorine and potassium), regulating water and electrolyte and acid-base balance of the body, affecting the nervous system and blood pressure. Sodium is an essential element for the proper growth. The proper dose of salt prevents overheating of the body and solar stroke. It provides the proper functioning of muscles and nerves the body. Chlorine in combination with sodium, is involved in the digestive process and maintains acid-base balance in the body, as antitoxin removes toxic products of metabolism in the liver. Salt is a flavour component and preservative of many foods, nutritional supplements and mixtures of electrolytes, available at

Dosage: no specific standards of consumption, used so as to provide sufficient amount of electrolytes to the body (sodium and chloride).




What is methylcobalamin?

Methylcobalamin is a biologically active form of vitamin B12. It is one of the two forms of this vitamin that may be used as cofactors in various reactions. It differs from popular cyanocobalamin in the presence of methyl group instead of cyanide, thanks to which it releases the organism from the need of neutralizing this harmful factor.

The methyl group from methylcobalamin may be transferred to homocysteine, thanks to which it comes back in the form of methionine in order to be further converted to SAMe, which is the main donor of methyl groups in our organism. These methyl groups may be then used in the processes of creatine production, in neurotransmitter metabolism and as DNA methylation, thanks to which we achieve proper energy level, better well-being and generally better condition of the organism. B12 is a coenzyme for three enzymes: isomerase, methyltransferase and dehalogenase.

Apart from the influence on the nervous system, the supply of vitamin B12 is also very important for the proper synthesis of red cells as well as hemoglobin and anemia prevention.


Methylcobalamin in mono-supplements and complex vitamin preparations may be found in the offer of



Biotin (vitamin H, co-enzyme R) is in a group of B vitamins, due to the presence of sulphur compounds it is involved in the synthesis of ascorbic acid (vitamin C). Also synthesized in the intestines. It enhances the production of hormones and regulates cholesterol levels. It reduces muscle pain. It prevents hair loss and graying of hair. It soothes the skin inflammations. No toxic effects. Often combined with other B group vitamins and vitamin A. The natural sources of biotin are: whole grain bread, yeast, eggs (yolk), milk, brown rice and cheese.

Daily demand: 100-300 mg per day




Calcium (element chem. symbol Ca, atomic no. 20, the group of alkaline earth metals) is the basic building substance of bones and teeth, in which stored is 99% of the element, in the form of hydroxylapatite. When building bones and teeth, phosphorus is very important in the right proportion. It is a base-forming element and activator of many enzymes (ATPase) necessary to release the energy of ATP. It has a significant effect on blood clotting and regulates blood pressure and neuromuscular conductivity. Thanks to the reduced permeability of cell membranes, it soothes the symptoms of food allergies. Calcium is actively involved in the metabolism of iron interacts with vitamins A, C and D and phosphorus, magnesium. Natural source of calcium are animal products (dairy products, sardines, salmon, sprats eaten with bones) and plant products (nuts, soybeans, sunflower seeds). Absorption takes place in the small intestine (less in the colon), it has an effect on the level of lactose, insoluble fibre, organic acids, alkalinity (low pH). The best absorption have organic compounds (lactates, amino acid chelates etc.). Obstructing the absorption of calcium is caused by: phytic acid and oxalic acid as well as excess fat. Scientific studies have confirmed that the combination of calcium, magnesium, boron and vitamin D in dose 3 mg / 24h effectively prevent osteoporosis. Supplements on the market are both mono-preparation supplements (enriched with vitamin D3) and multi-component supplements, available at
Calcium deficiency disorders manifested in the construction of the bones (osteoporosis) and iron metabolism. The symptoms are: rickets, cramps and muscle tremor, osteoporosis.
Excess result
ing from an overdose of calcium supplements containing vitamin D3 for children and adults overdose of calcium (hypercalcemia). Symptoms of hypercalcemia are: lack of appetite, vomiting and constipation.
The dosage administered in various publications
are inconsistent: 800 - 1000 mg / 24 h (100 - 500 mg / 24h)

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