11 best thorne research vitamin c vitamins

Product description

A synergistic blend of vitamin C and citrus bioflavonoids from oranges.



Since 1984, Thorne has set the standard for the exceptional formulation and quality manufacturing of nutritional supplements. Thorne delivers premium, science-based products, a health diagnostics technology platform, and the latest in medical education. With more than 350 products, Thorne is the most dispensed brand by 30-to 40-year-old health-care practitioners. Thorne is dedicated to improving the health of our community as well as increasing the knowledge of nutritional health and wellness. Since 2012, Thorne has partnered with educational institutes and local charities to donate more than $1M in products and profits.



Thorne products do not contain any unnecessary binders, coatings, disintegrants, fillers, or lubricants (including magnesium stearate) that could impair absorption. Thorne adheres to the FDA’s current Good Manufacturing Practices (cGMPs) and has the highest number of NSF Certified for Sport products which test for more than 200 banned substances for elite athletic competitions.

• Paired In Nature: Citrus bioflavonoids optimize the benefits of vitamin C*
• No Corn Starch: Not diluted with corn starch, as found in other vitamin C products on the market
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.
• Thorne products contain ingredients from the purest sources worldwide. Flavors, colors, preservatives, and sweeteners are derived from natural sources. Our products never contain gluten, Genetically Modified Organisms (known as GMOs), artificial preservatives, stearates, wheat, rye, barley, eggs, or nuts. This product does not contain soy, dairy, corn, yeast, sugar, or magnesium stearate.
• Thorne's commitment to integrity and science-backed products has helped us earn the trust of thousands of health-care professionals, U.S. National Teams, the Mayo Clinic, and families around the world.

User questions & answers

Product description

With calcium, magnesium, and potassium.



Since 1984, Thorne has set the standard for the exceptional formulation and quality manufacturing of nutritional supplements. Thorne delivers premium, science-based products, a health diagnostics technology platform, and the latest in medical education. With more than 350 products, Thorne is the most dispensed brand by 30-40 year old health-care practitioners. Thorne is dedicated to improving the health of our community as well as increasing the knowledge of nutritional health and wellness. Since 2012, Thorne has partnered with educational institutes and local charities to donate more than $1M in products and profits.



Thorne products do not contain any unnecessary binders, coatings, disintegrants, fillers, or lubricants (including magnesium stearate) that could impair absorption. Thorne adheres to the FDA’s current Good Manufacturing Practices (cGMPs) and has the highest number of NSF Certified for Sport products which tests for more than 200 banned substances for elite athletic competitions.

• Easy To Take: The easiest way to take a higher amount of vitamin C
• Easy On The Stomach: A buffered vitamin C supplement for individuals with a sensitive or compromised digestive system
• Immune: For immune function and antioxidant support*
• Collagen/Bones: Helps maintain healthy bones and connective tissue*
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

User questions & answers

• Antioxidant: A water-soluble antioxidant
• Immune: Promotes healthy immune function*
• Collagen: Promotes the formation of connective tissue*
• Injury/Wound Healing: Supports injury repair and post-surgery wound healing*
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

Product features

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Plus Vitamin C: A convenient way to supplement with high amounts of these minerals, plus added benefit of vitamin C
• Bones/Muscles: Supports bone and muscle health*
• Effervescent: Powder effervesces when mixed with water, resulting in formation of optimally absorbed citrate, ascorbate, and glycinate minerals
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.
• Thorne's commitment to integrity and science-backed products has helped us earn the trust of thousands of health-care professionals, U.S. National Teams, the Mayo Clinic, and families around the world.

User questions & answers

Product features

Thorne Bestseller

Thorne has been trusted by health-care practitioners, U.S. National Teams, and families around the world for more than 30 years. Thorne Bestsellers are a testament to Thorne's mission to provide high-quality supplements that are tested for quality, safety, and efficacy.

Unique Formula

The ratio of calcium and magnesium is designed for individuals who need higher amounts of calcium but can’t tolerate an equal amount of magnesium due to its laxative-like characteristic.*

Convenient Protocol

The powder form is easy to consume, mixes well into drink of choice, and is convenient to take.

Purest Ingredients

There are no unnecessary fillers or additives in Thorne products. Thorne is committed to providing high-quality supplements that contain research-backed ingredients, in efficacious amounts, that retain the potency to meet label claims until the day of expiration.

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Red Blood Cells: A complete blood-building formula*
• Non-Constipating Iron: A well-absorbed, non-constipating form of iron -- iron bisglycinate -- from Albion Laboratories
• Optimal Forms: active, tissue ready, well-absorbed nutrients -- folate, vitamin B12, and iron
• Vitamin C: to enhance the absorption of iron
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

User questions & answers

Product features

Unique Formula

Ferrasorb provides 36 mg of elemental iron per capsule, plus the active forms of folate and vitamins B6 and B12, which are essential for blood-building. Vitamin C optimizes iron absorption.

Well-Researched Benefits

Iron deficiency can manifest as weakness, fatigue, shortness of breath on exertion, dizziness, tinnitus, spots before the eyes, drowsiness, irritability, infrequent menses, and loss of libido.

Purest Ingredients

There are no unnecessary fillers or additives in Thorne supplements. Thorne is committed to providing high-quality supplements that contain research-backed ingredients, in efficacious amounts, that retain the potency to meet label claims until the day of expiration.

Thorne Bestseller

Thorne has been trusted by health-care practitioners, U.S. National Teams, and families around the world for more than 30 years. Thorne Bestsellers are a testament to Thorne's mission to provide high-quality supplements that are tested for quality, safety, and efficacy.

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Grapeseed Extract: OPCs are important health-promoting flavonoids from grape seed*
• Optimal Aborption: OPCs bound to phospholipids for optimal absorption
• Blood Vessels: Strengthens blood vessels to decrease bruising*
• Antioxidant: Contains important antioxidant flavonoids*
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

User questions & answers

Product features

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Adrenal Support: Extra vitamin B5 to support the adrenal glands*
• Stress: Supports the body’s natural ability to manage stress*
• Complete: Optimal balance of essential B vitamins
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.
• Thorne's commitment to integrity and science-backed products has helped us earn the trust of thousands of health-care professionals, U.S. National Teams, the Mayo Clinic, and families around the world.

User questions & answers

Product features

Thorne Bestseller

Thorne has been trusted by health-care practitioners, U.S. National Teams, and families around the world for more than 30 years. Thorne Bestsellers are a testament to Thorne's mission to provide high-quality supplements that are tested for quality, safety, and efficacy.

Clinically Studied

Stress B-Complex contains an optimal balance of essential B vitamins.

Well-Researched Benefits

Supplies 250 mg of pantothenic acid, a starting material for the synthesis of coenzyme A, which is important for fat metabolism and the synthesis of adrenal hormones.*

Unique Formula

Supplies 250 mg of pantothenic acid, a starting material for the synthesis of coenzyme A, which is important for fat metabolism and the synthesis of adrenal hormones.*

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Vitamin D: Contains 10,000 IU of vitamin D3 per capsule
• Multiple Functions: Supports immune function and promotes cardiovascular, muscle, and bone health*
• Lactose-Free: Contains no lactose, BHT, BHA, sodium benzoate, or sorbic acid, which can be detrimental to sensitive individuals
• Also available in 1,000 IU and 5,000 IU capsules
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

User questions & answers

Product features

Thorne Bestseller

Thorne has been trusted by health-care practitioners, U.S. National Teams, and families around the world for more than 30 years. Thorne Bestsellers are a testament to Thorne's mission to provide high-quality supplements that are tested for quality, safety, and efficacy.

Well-Researched Benefits

Thorne’s Vitamin D supplements support healthy bones and muscles, cardiovascular function, and immune function.*

Free of Additives

Unlike many vitamin D supplements, Thorne’s vitamin D products contain no lactose or preservatives.

Convenient Protocol

Easy to take protocol. Take 1 capsule one to three times daily or as recommended by your health professional.

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Multiple Functions: Supports healthy bones and muscles, cardiovascular health, and immune function*
• Liquid: Allows for easy dosing for children and adults
• Natural Preservative: Preserved with mixed tocopherols (natural vitamin E)
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.
• Thorne's commitment to integrity and science-backed products has helped us earn the trust of thousands of health-care professionals, U.S. National Teams, the Mayo Clinic, and families around the world.

User questions & answers

Product features

Free of Additives

Vitamin D Liquid is preserved with natural vitamin E for freshness and is free of additives.*

Purest ingredients

There are no unnecessary fillers or additives in Thorne supplements. Thorne is committed to providing high-quality supplements that contain research-backed ingredients, in efficacious amounts, that retain the potency to meet label claims until the day of expiration. Vitamin D Liquid is free of sesame oil and soy oil.

Convenient Protocol

Thorne’s Vitamin D Liquid can be mixed with a food or a beverage for ease of use for all ages.

Thorne Bestseller

Thorne has been trusted by health-care practitioners, U.S. National Teams, and families around the world for more than 30 years. Thorne Bestsellers are a testament to Thorne's mission to provide high-quality supplements that are tested for quality, safety, and efficacy.

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• Active B6: The active form of vitamin B6 that is readily used by the body
• Multiple Functions: An essential cofactor for the synthesis of amino acids and numerous neurotransmitters (brain chemicals)*
• PMS: Pairs with magnesium for support of women with PMS*
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.
• Thorne's commitment to integrity and science-backed products has helped us earn the trust of thousands of health-care professionals, U.S. National Teams, the Mayo Clinic, and families around the world.

Product features

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.

• More B6: Complete vitamin B complex with extra B6
• Active, Tissue-Ready: Unlike many B vitamin products, contains the B vitamins in their active forms for optimal absorption
• Nerve/Brain: Extra B6 supports brain and neurological function*
• PMS: Helps relieve symptoms of PMS*
• Free From: Every Thorne product is made with the purest possible ingredients - without gluten or other major allergens (eggs, tree nuts, peanuts). This product also contains no soy, dairy, yeast, shellfish, or fish.

User questions & answers

Product features

Sourcing Exceptional Ingredients

We develop better standards for higher quality ingredients. Thorne cares deeply about where our ingredients come from. We partner only with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients means better potency, absorption, and digestibility - and ultimately better health.

Manufacturing the Right Way

We manufacture our own products to ensure full supply chain transparency. For more than 30 years, we have invested in clean manufacturing practices. We refuse to use ingredients that can inhibit absorption. We perform our final production in the United States. Our Charleston, SC facility is third-party certified.

Four Rounds of Testing

We run four rounds of testing for each of our products. We have invested in two state-of-the-art in-house laboratories that allow us to conduct four rounds of testing, while most competitors test only one or two times. We test our raw materials, in-process batches, finish products, and product stability for each product.

Thinking Sustainably

We're thinking sustainably to protect our environment. We believe the environment should never be compromised for the sake of business gain. At Thorne, we believe that doing our part to protect the environment and its most valuable resources goes hand in hand with our product quality standards.