Doctor's Best - Vitamin C with Quali-C 500 mg. - 120 Vegetarian Capsules
Doctor's Best Vitamin C with Quali-C supports optimal immune function. Doctor's Best Vitamin C helps neutralize oxidative stress. Best Vitamin C featuring Quali-C provides a brand of ascorbic acid manufactured in Scotland prized for its quality and reliability. Ascorbic acid is invaluable to the body for its role as an electron donor, supporting numerous metabolic enzymes in addition to enhancing the body's total antioxidant potential. Essential for the synthesis of collagen, carnitine, and certain neurotransmiters, ascorbic acid can also aid in iron absorption. Research suggests that this vitamin supports many additional areas of health, including the cardiovascular and immune systems.
Vitamin C is essential to the biosynthesis of the metabolic facilitator L-carnitine, the neurotransmitter norepinephrine, and the main connective tissue in the body, collagen. While these functions are obviously critical for our health, this vitamin is most widely revered for its role as a reducing agent (an electron donor), serving as a co-factor for hydroxylases (enzymes) in addition to enhancing the body’s total antioxidant potential. As a reducing agent, ascorbate also can aid in the absorption of dietary nonheme iron, helping those who need more iron from their daily intake.
- Science-based nutrition
- Helps neutralize oxidative stress
- Supports optimal immune function
Enhances the Body's Antioxidant Network
Vitamin C is a key compound in the body’s “antioxidant network,” a chain of synergistic, inextricability linked, well-studied antioxidants that includes glutathione (GSH) and vitamin E. When vitamin E uses its antioxidant function in neutralizing free radicals, it also loses this antioxidant function. Vitamin C can change this status; it can regenerate vitamin E back to its native form, and is thought to “spare” glutathione in the body as well. Importantly, when ascorbate donates an electron and becomes itself oxidized, or “consumed,” the ascorbate radical is relatively harmless. In a double-blind, placebo-controlled study in which blood GSH was measured in healthy subjects at several stages, 500 mg of vitamin C taken daily for 2 weeks significantly raised erythrocyte (red blood cell) glutathione levels. The researchers concluded that vitamin C supplementation at that level can benefit the overall antioxidant capacity of the blood.4 In another study of similar design, 1000 mg of vitamin C taken daily for 4 weeks bolstered vitamin E and glutathione content in erythrocyte cell membranes, compared with placebo.
The highest concentrations of vitamin C in the body are found in the central nervous system (in neurons of the brain & spinal cord) and the adrenal glands. Although the presence of ascorbate in neurons is in part explained by its neuromodulatory enzyme activity, its high concentration suggests that vitamin C is so greatly retained by neurons in order to address the higher rates of oxidative metabolism experienced by the brain. This has led to the conclusion that under normal conditions, vitamin C helps safeguard the integrity of neurons (and therefore the brain), largely through neutralization of the free radicals of reactive oxygen species (ROS). Low levels of blood vitamin C and the resulting accumulation of ROS are thought to be detrimental—especially to aging populations.
Supports the Cardiovascular and Immune Systems
Most prospective studies assessing vitamin C intake in large numbers of people who are followed over time indicate that the highest intakes of vitamin C are associated with enhanced cardiovascular benefits. In addition, some large studies of healthy individuals who take vitamin C supplements suggest that supplementation supports healthy heart function. The Nurses’ Health Study of more than 85,000 women followed for over 16 years found vitamin C intakes of more than 359 mg per day from diet plus supplements or from supplements alone were associated with a more favorable cardiovascular health status.7 In a recent review of studies in which more than 290,000 healthy adults were followed for an average of 10 years, those who took more than 700 mg per day of supplemental vitamin C had a substantially better cardiovascular profile than those who did not take vitamin C supplements.
Oxidative stress is a central component of cardiovascular health, and vitamin C acts vigorously to counteract multiple avenues of oxidation that detract from cardiovascular health.9 Nitric oxide (NO) produced by endothelial cells (lining blood vessel walls) helps to maintain cardiovascular homeostasis and to safeguard blood vessels. Ascorbate helps to protect the normal NO biosynthesis pathway, which is easily disrupted by ROS.
High levels of certain proteins in the blood serve as indicators of disruptions to both cardiovascular and immune system health. In a study of 3,258 healthy men, levels of vitamin C in the blood have been found to be inversely associated with these protein markers of unbalanced immune activation.
In a study examining the blood of 240 healthy subjects, the concentration of glutathione and ascorbate was measured in lymphocytes.11 Interestingly, the vitamin C levels of the lymphocytes varied significantly depending on the season (ascorbate levels were lower in the winter), confirming earlier research in which investigators had reported fluctuations in blood vitamin C levels with the seasons. The researchers propose that vitamin C supplementation will not only increase levels of ascorbate in lymphocytes, but GSH levels as well. Although not a controlled clinical trial, the results here are one more piece of the immune system puzzle, and they also hint at what time of year vitamin C supplementation may be most beneficial.
Frequently Asked Questions
Does cellulose interfere with the absorption of supplements?
Dietary fiber in general is known to change intestinal viscosity, nutrient absorption, transit time, and gut hormones. Although there is some evidence from animal studies that large amounts of cellulose in the diet (6-12% of diet) can interfere with nutrient absorption (particularly minerals), there is no evidence that the small amount in capsules interfere with nutrient absorption, as there are many pharmacokinetic studies that have been conducted with nutrients in cellulose capsules, demonstrating the ability of the nutrients to be effectively absorbed.
What is HPLC?
HPLC stands for "High Performance Liquid Chromatography." This is an analytical lab testing method that is used to quantify the active ingredients. It is considered to be a very sensitive and accurate test. HPLC testing is a tool recognized as a quality benchmark for herbal extracts.
What is cellulose and modified cellulose produced from?
Southern pine and spruce.
What are the other ingredients and why are they used?
These are used as flow agents and aid in the production to keep the machinery running smoothly and the capsules filling correctly. Similarly for the croscarmellose sodium, which is cellulose (sourced from the cell walls of green plants), and is used to help disintegrate the tablet in the stomach.
Is there a limit to how many vitamins can be taken safely in one day?
While our bodies need vitamins and minerals, like other things, if taken in large amounts they may adversely affect health. Large amounts of anything can be toxic. It is important to follow all label directions and discuss any concerns with your physician.
I am somewhat confused on how to take the DRB products. On many of the labels the Suggested Adult Use will list something along the lines of: Take 2 capsules daily, but it does not state whether they should be taken together or separately. What is the correct usage?
Unless otherwise specified on the label, the product may be taken together or separately.
What is modified cellulose and is it safe?
The cellulose is derived from alpha cellulose from softwood pulp. This softwood pulp may be derived from hemlock, spruce or other soft woods. It is made by cooking raw plant fiber in an aqueous solution to separate the cellulose, and then purified. It then goes through extra processing to further break down the fiber. The finished product contains no residual solvents. Excipients are needed to make the materials flow into the capsule and are extremely minute in amounts and are safe.
Can Vitamin C be taken at the same time as Magnesium Glycinate on an empty stomach? Will the ascorbic acid react with the magnesium glycinate, resulting in magnesium ascorbate? If not, why not?
There is no concern with taking magnesium glycinate and ascorbic acid together on an empty stomach, i.e. no interaction concerns or known interference with absorption. Magnesium glycinate is a "chelated" form of the mineral (has a chelate bond between Magnesium and glycine), making it very stable in the body (a stronger bond than the ionic bond in ascorbic acid). Therefore, while the ascorbic acid may dissociate, the magnesium glycinate is most likely absorbed in tact, making it unlikely that the Magnesium ascorbate would form.
About Doctor's Best
Doctor's Best firmly believes in the integration of science research and traditional wisdom as the way that nutritional and herbal supplements will reach their exciting potential. Founded in 1990 by a pioneering physician committed to science-based alternative health care, Doctor's Best offers only the most important nutritional supplements. Careful research and precise formula development keeps us at the leading edge of quality, effectiveness, and innovation. Containing the finest quality raw materials from around the world, Doctor's Best supplements embody the best that traditional knowledge and current scientific research have to offer in the field of therapeutic nutrition. Countless hours have been spent analyzing scientific literature to provide sound alternatives to the proliferation of questionable supplements in the marketplace. Traditional wisdom , up-to-date research, product quality you can trust, all the information you need to develop smart strategies for achieving optimal health and well-being.