Navigating the Supplement Spectrum: A Guide to Vitamin Supplementation

Introduction:

Vitamins are essential organic compounds that are vital for the body’s functions. There are two groups of vitamins – water soluble (B vitamins and vitamin C) and fat soluble vitamins (Vitamins A, D, E, and K). Water soluble vitamins depend on energy requiring systems, are transported in the blood, and readily excreted in urine. This means these compounds need to be regularly consumed in our diet, as there is no long term storage for most of these vitamins. On the other hand, fat soluble vitamins are stored in the liver and fat tissue, so it takes longer for these vitamins to develop a deficiency, and excretion of these vitamins are limited. Fat soluble vitamins require dietary fat to be absorbed, and can be absorbed without help from transport systems.

Water Soluble Vitamins: B Vitamins and Vitamin C

Thiamin (Vitamin B1): Energy Production and Metabolism

Vitamin B1 is important for energy production, cell growth, and metabolism, and functions as a coenzyme in energy metabolism. Vitamin B1 is widely distributed in foods, including meat, legumes, and fortified grains.

B1 deficiency is rare; however, people with Crohn's disease, anorexia, alcoholism, or people undergoing kidney dialysis may be deficient. Deficiency symptoms include headache, nausea, fatigue, irritability, depression, and abdominal discomfort (1).

When to Consider Supplementation:

Beriberi: disease caused by thiamine (B1) deficiency. Thiamin deficiency is related to a difficulty digesting carbohydrates, causing pyruvic acid to build up in the bloodstream, causing beriberi – a loss of mental alertness, difficulty breathing, and heart damage.
- Symptoms: weight loss, altered heart rate, confusion, decreased short term memory, and irritability

Riboflavin (Vitamin B2): Energy Production and Metabolism

Vitamin B2 helps to convert food into fuel, and is used to produce energy. Vitamin B2 also acts as an antioxidant, fighting damaging particles in the body (2). Vitamin B2 is found in animal foods, such as milk, milk products, eggs, meat, and legumes.

B2 deficiency is rare and is rarely seen on its own. Most healthy people get enough riboflavin, however those with a poor diet (such as the elderly or alcoholics) may be at risk of deficiency.

When to Consider Supplementation:

Ariboflavinosis: disease caused by riboflavin (B2) deficiency, usually seen in combination with other B vitamin deficiencies.
- Symptoms: inflammation of eyes, lloyds, mouth; cracking at corners of mouth; about 2 months of riboflavin-poor diet

Niacin (Vitamin B3): Energy Production, Metabolism, Digestion, Absorption, and Transport

Vitamin B3 is made and used by the body for energy production and helps maintain the functions of the nervous system, digestive system, and skin. Niacin (B3) is found in fish, tuna, halibut, and meats.

B3 deficiency is rare. Deficiency is mainly caused by alcoholism.

When to Consider Supplementation:

Pellagra: condition caused by severe niacin deficiency.
- Symptoms: cracked, scaly skin, dementia, and diarrhea (3).

Niacin toxicity is more common than niacin deficiency because niacin precursors are used to treat high cholesterol levels and heart disease. Toxicity symptoms include redness, burning, itching, heartburn, nausea, and vomiting.

Pantothenic Acid (B5): Functions Everywhere in the Body

Vitamin B5 is known for many different functions – energy production, metabolism, cholesterol production, hormone functions, digestion, and more. B5 is present in almost all foods and is found in plant and animal foods.

B5 deficiency is extremely rare, and is only seen in cases of severe malnutrition.

Vitamin B6: Energy Metabolism and Beyond

Vitamin B6 is vital for energy metabolism and neurotransmitter synthesis. B6 functions in amino acid metabolism, neurotransmitter synthesis, and immune function. B6 is found in fish, poultry, nuts, legumes, potatoes, and bananas.

It is rare to have a significant deficiency of B6; however, many people may be mildly deficient, especially children and the elderly (4). Symptoms of deficiency include muscle weakness, neurological symptoms, and anemia. People who eat a balanced diet should meet the daily requirement for vitamin B6 without taking a supplement.

When to Consider Supplementation:

Restricted diet or malabsorption issues
Deficiency: Can lead to anemia, skin issues, and neurological problems.
RDA**:** 1.3-2 mg for adults.

It is important to note that toxicity can be seen at high dose supplementation, which are available over the counter and can approach UL (100 mg/day). This may cause pain and numbness in extremities, and may cause an inability to walk at especially high amounts.

Biotin (Vitamin B7): Digestion, Absorption, and Transport

Biotin functions as a coenzyme and is involved in cell proliferation, DNA repair, and signaling as well as aiding in digestion. Biotin is found in liver, soybeans, and eggs.

Biotin deficiency is very rare, but can be seen in those who eat raw egg whites. Supplementation is generally not needed.

Folate (B9): Amino Acid Metabolism, Energy Metabolism, and Blood Levels

Folate functions as a coenzyme typically generated from amino acid metabolism and functions in a variety of reactions in the body. Folate also works with B12 to help make red blood cells and aid in the function of iron in the body. Folate comes from mushrooms, green vegetables, fortified foods, and enriched flours.

It can be common to have low levels of folic acid, specifically in alcoholism, inflammatory bowel disease, and celiac disease (5).

When to Consider Supplementation:

Deficiency: symptoms include poor growth, inflammation, gingivitis, and more.
Megaloblastic macrocytic anemia: red blood cells that are fewer than normal, larger, and immature and also occurs with vitamin B12 deficiency, resulting from abnormal DNA synthesis and failure of blood cells to divide properly
Pregnancy: pregnant women need more folic acid to lower the risk of neural tube defects. Pregnant women should get 600 mcg of folic acid per day (5).

Vitamin B12 (Cobalamin): Energy Metabolism, Excretion, Digestion, and Absorption

Vitamin B12 functions in digestion, protein metabolism, nervous system functions, and excretion. Unlike other water-soluble vitamins, B12 can be stored in the liver for relatively long periods of time. B12 comes from animal products and dairy.

Because vitamin B12 is not generally present in plant foods, deficiency can be more commonly seen in those following vegan diets. However, fortified breakfast cereals and some nutritional yeast products are a readily available source of vitamin B12. It is important to note that the body absorbs vitamin B12 from animal sources more efficiently than B12 from plant sources, and non-animal sources of vitamin B12 have different amounts of B12 (6).

When to Consider Supplementation:

Deficiency: B12 deficiency occurs when the body does not get or is not able to absorb the vitamin. Symptoms of deficiency include anemia, dementia, loss of balance, numbness, weakness
Megaloblastic macrocytic anemia: red blood cells that are fewer than normal, larger, and immature and also occurs with vitamin B9 deficiency, resulting from abnormal DNA synthesis and failure of blood cells to divide properly
People over the age of 50 may be at higher risk of deficiency caused by lack of intake or ability of the body to absorb the vitamin.
Vegans or vegetarians may have difficulty consuming adequate amounts of B12 due to lack of intake of animal products.
Those with stomach or intestinal surgery or digestive system conditions may have difficulty absorbing the vitamin, causing deficiency.
Daily Intake
- RDA for Males and Females: 2.4 mcg/day
- Pregnant women: 2.6 mcg/day
- Breastfeeding women: 2.8 mcg/day

Vitamin C (Ascorbic Acid): Antioxidant, Growth and Repair

Vitamin C functions in growth and repair of all tissues in your body. It is also an antioxidant, which is important in protecting from damage in the body. Vitamin C is found in citrus fruits, broccoli, and tomatoes.

Vitamin C deficiency is rare, however low levels can be common, especially in smokers (7).

When to Consider Supplementation:

Deficiency symptoms: dry and splitting hair; gingivitis; rough, dry, or scaly skin; bruising; nose bleedings; infections
Scurvy: extreme case of Vitamin C deficiency caused by impaired hydroxyproline and hydroxylysine synthesis needed for collagen formation

It is important to note that too much Vitamin C intake can cause toxicity. It is common to have a high intake of Vitamin C, which in excess, is readily excreted in the urine. However, too much excess intake can cause toxicity symptoms, such as osmotic diarrhea, kidney stones in renal disease patients, and iron toxicity for patients with iron metabolic disease.

Fat Soluble Vitamins: Vitamins A, D, E, and K

Vitamin A: Vision and Eye Health

Vitamin A is important for vision and eye health, cellular differentiation, gene expression, growth, reproduction, bone development, and supports the immune system. Vitamin A comes from two sources: retinoids and carotenoids. Retinoids are found in animal products, fish, and liver oil of fish. Carotenoids are red, orange, and yellow lipids found mainly in plants (8).

Vitamin A deficiency is rare in the United States. However, chronic Vitamin A deficiency is associated with severe malnutrition.

When to Consider Supplementation:

Xerophthalmia: clinical symptom of vitamin A deficiency, causing dryness of the aye, abnormalities, and night blindness.

Toxicity can be caused by chronic intake of 10 times RDA (tolerable upper intake: 3000 ug). Toxicity can cause nausea, vomiting, double vision, headaches, etc. Toxicity can also cause birth defects and liver damage. Lastly, toxicity of vitamin A can cause hypercalcemia, an orange discoloration of the skin; however, this is usually not damaging to the liver.

Vitamin D: The Sunshine Nutrient

Vitamin D is crucial for bone health, immune function, and overall well-being. While sunlight is a natural source, individuals with limited sun exposure or those residing in areas with minimal sunlight may benefit from supplementation. Regular testing can determine if vitamin D levels are below the optimal range. Vitamin D is essential for bone health, immune system support, and regulation of calcium and phosphorus. Sources of Vitamin D include sunlight, fatty fish, fortified foods, and supplements.

Vitamin D deficiency is very common worldwide, and may cause bone issues, such as rickets (failure of bone mineralization in infants and children) and osteomalacia (reduced calcium absorption and bone resorption resulting in soft bones in adults).

When to Consider Supplementation:

Limited sun exposure
Insufficient dietary intake
Deficiency: Can lead to bone problems, weakened immune system, and other health issues.
Daily Intake: Varies, but a common recommendation is 600-800 IU.

Toxicity can be caused by exceeding the tolerable upper limit of 4000 IU. This can cause hypercalcemia, meaning too much calcium in the blood leading to the calcification of soft tissue.

Vitamin E: Functions in Reproduction and has an Antioxidant Role

Vitamin E is important for reproduction by providing maintenance in membrane integrity, and plays an important role as an antioxidant in lipid environments. Vitamin A is found in plant oils.

Deficiency of Vitamin E is rare, but can be found in people with fat malabsorption disorders or in premature infants. Symptoms include skeletal muscle pain, weakness, ceroid pigment accumulation, hemolytic anemia, neurological problems, loss of vibratory sense, loss of coordination of limbs.

Vitamin K: Protein Function, Blood Clotting, and Bone Mineralization

Vitamin K plays a role in protein binding, blood clotting, and bone mineralization. Dark leafy greens are a great source of Vitamin K. Vitamin K can also be found in most vegetables and legumes.

Vitamin K deficiency is rare in healthy adults, but can be found in those with bleeding episodes.

If you are taking Warfarin, a blood thinner, it is important to watch for Vitamin K intake. Warfarin can inhibit enzymes by reducing active Vitamin K in blood clotting. In this case, it is important to keep Vitamin K levels stable.

Conclusion

When considering vitamin supplementation, it is important to consult with a doctor or registered dietitian. Vitamin supplementation is not always needed, and can cause toxicity in excess amounts.

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