Vitamins

25-hydroxy Vitamin D2 (25(OH)D2) is one of the two main forms of vitamin D measured in the blood, the other being 25-hydroxy Vitamin D3. While Vitamin D3 is typically produced in the skin through sunlight exposure and obtained from animal-based sources, Vitamin D2 is derived from plant-based sources and supplements. 25(OH)D2 is converted in the liver from ergocalciferol (Vitamin D2) and reflects the body's intake of this form of the vitamin. It plays a role in calcium and phosphate metabolism, immune function, and overall bone health. Although Vitamin D2 is less potent and has a shorter half-life than Vitamin D3, both forms contribute to total vitamin D status.

25-hydroxy Vitamin D3 (25(OH)D3) is the primary circulating form of vitamin D in the human body and the most accurate marker for assessing vitamin D status. It is synthesized in the skin upon exposure to UVB radiation from sunlight and can also be obtained from dietary sources such as fatty fish, egg yolks, and fortified foods. Once produced or ingested, vitamin D3 is converted in the liver to 25(OH)D3, which is the major storage form of vitamin D. This form is essential for maintaining calcium and phosphate balance, supporting bone health, and modulating immune, endocrine, and neuromuscular functions.

Biotin, also known as vitamin B7, is an essential nutrient that supports the body’s ability to convert food into energy. It plays a key role in metabolizing fats, carbohydrates, and proteins, while also promoting healthy skin, hair, and nails. Although biotin deficiency is uncommon, supplements are frequently used to improve hair and nail strength.

CoQ10 (Coenzyme Q10) is a vital compound that plays a key role in energy production within every cell of the body. It also functions as a powerful antioxidant, helping to protect cells from oxidative damage. CoQ10 is essential for supporting overall health and proper cellular function.

Folate, also called folic acid, is an essential B-vitamin important for cell growth and DNA production. It plays a critical role during pregnancy to help prevent birth defects. Folate is naturally found in leafy greens, fruits, beans, and fortified foods. Supplements are often used during pregnancy and certain health conditions. A deficiency in folate can cause fatigue and weaken the immune system.

Holotranscobalamin (holoTC), also known as active vitamin B12, is the form of vitamin B12 bound to transcobalamin, a transport protein in the blood. It is the only form that can be taken up by cells through receptor-mediated endocytosis, making it directly available for cellular functions. Measuring holoTC provides a more accurate indication of recent vitamin B12 status than total vitamin B12, as it reflects the fraction that is immediately available for use by the body.

Nicotinamide, also known as niacinamide, is a form of vitamin B3 that plays a key role in cellular metabolism. It supports the health of the skin, nervous system, and digestive system. Unlike nicotinic acid, another form of vitamin B3, nicotinamide does not cause skin flushing. It is commonly used to treat skin conditions such as acne and is being researched for its potential benefits in neurodegenerative diseases and cancer prevention. Naturally found in foods like meat, fish, and green vegetables, nicotinamide is also available as a supplement and is widely included in skincare products.

Nicotinic acid (niacin or vitamin B3) is an essential nutrient that helps convert food into energy and supports healthy skin, nerve function, and digestion. It’s naturally found in foods like meat, fish, and grains, and can also be made from the amino acid tryptophan. A deficiency in nicotinic acid can cause pellagra, a condition marked by diarrhea, dermatitis, and dementia.

Vitamin A is an essential nutrient that supports vision, immune defense, skin integrity, and reproductive health. It plays a key role in low-light vision, maintaining healthy mucous membranes, and promoting normal growth. Found in foods such as carrots, sweet potatoes, leafy greens, liver, and dairy products, Vitamin A deficiency can lead to impaired vision, reduced immunity, and skin issues.

Vitamin B12, or cobalamin, is a water-soluble vitamin vital for red blood cell production, nervous system function, and energy metabolism. It uniquely contains the metal cobalt and is naturally found in animal-based foods such as meat, fish, poultry, eggs, and dairy. Because B12 is limited in plant-based diets, vegetarians and vegans often require fortified foods or supplements to meet their needs.

Vitamin B3 (Niacin) is an essential nutrient that helps convert food into energy and supports the health of the skin, nervous system, and digestive tract. It is found in foods like meat, fish, poultry, and whole grains. Niacin also contributes to maintaining healthy cholesterol levels and overall metabolic function. Deficiency may lead to fatigue, skin problems, and cognitive issues, and supplementation may be necessary in certain health conditions.

Vitamin B5, also called pantothenic acid, is a vital nutrient that helps the body convert food into energy by supporting the metabolism of carbohydrates, proteins, and fats. Found in foods like meats, avocados, broccoli, and whole grains, it plays an important role in maintaining healthy skin, aiding wound healing, supporting the nervous system, and helping reduce stress.

Vitamin D is a fat-soluble vitamin essential for maintaining healthy bones and teeth, supporting the immune system, and aiding muscle function. Unlike most vitamins, the body can produce vitamin D when the skin is exposed to sunlight, making it unique in how it’s obtained and utilized.

Vitamin E is a fat-soluble antioxidant that helps protect cells from damage and supports immune function. It also plays a key role in maintaining healthy skin and blood vessels. Vitamin E is commonly found in foods such as vegetable oils, nuts, seeds, and green leafy vegetables. Although deficiency is uncommon, it can lead to neurological problems.