Vitamin C, also known as L-ascorbic acid, is an antioxidant and an essential nutrient that the body cannot synthesize on its own.

It can capture and neutralize free radicals. Vitamin C can react with free radicals and convert them into harmless substances, thus effectively reducing their number and damage. Therefore, vitamin C is an important antioxidant that helps protect the body from free radical damage.

Vitamin C participates in many physiological processes, such as improving immune system function, promoting iron absorption, detoxification, tissue repair, etc. Vitamin C is abundant in food, mainly from fruits and vegetables.

The Importance of Vitamin C

Vitamin C is an essential nutrient that the body cannot synthesize on its own because of the lack of an enzyme called L-Gulono-γ-lactone oxidase, which plays a key role in the synthesis of vitamin C. Therefore, it must be obtained from food or supplements. It has many important functions in the body, and vitamin C is very important for human health, providing a variety of protections and supports.

Benefits of Vitamin C for Health
・Promote Immune System Health
Vitamin C can inhibit the formation of free radicals, protect cells from oxidative damage, and enhance cell signal transduction. In addition, vitamin C can promote the production and activation of white blood cells, thus improving the body's immunity to viruses and bacteria. It can also increase the activity of antigen-presenting cells, thus improving the body's immune defense against diseases.

・Beneficial to Cardiovascular Health
Vitamin C can lower blood pressure, protect the vascular wall, and prevent cardiovascular diseases. Some studies have found that vitamin C can reduce blood pressure by inhibiting the production of angiotensin, thus reducing vascular tension. Vitamin C can also reduce blood pressure by inhibiting the production of angiotensin.

・Anti-Free Radical Damage
Vitamin C has the ability to neutralize free radicals and is an antioxidant that can bind to free radicals and neutralize them, preventing them from causing damage to cells. Vitamin C has a role in preventing cell damage because it has a strong antioxidant effect and can resist the toxicity of oxidants and protect cells from oxidative damage, thus preventing cell damage. In addition, vitamin C can also promote cell repair and regeneration, enhance cell resistance, and prevent cell damage.

・Help Detoxification
Vitamin C can help the liver detoxify and protect liver health. Vitamin C has antioxidant properties and can reduce the oxidative effect of toxins in the liver, improve the liver's metabolic capacity, promote liver detoxification, and protect liver health. In addition, vitamin C can also promote the production of liver detoxification enzymes, improve the liver's detoxification capacity, and thus protect liver health.

The effect of Vitamin C on the immune system
・Promote the generation and activity of T cells and macrophages
T cells refer to T lymphocytes, which are the main cells involved in memory immunity and cell-mediated immunity. T cells identify virus-infected cells and cancer cells, recognize and kill infected or malignant cells, thus protecting the human body from diseases.

Macrophages refer to macrophages, which are the main cells involved in passive immunity. Macrophages can protect the human body from diseases by phagocytosing bacteria, viruses, cancer cells and other exogenous substances.

In general, T cells and macrophages are two important cells in the human immune system, which are involved in the protection of the human body against viruses, bacteria, cancer cells and other exogenous substances, and maintain human health.

・Anti-infection: Vitamin C can improve the body's immunity and prevent infection.

The effect of Vitamin C on skin and eyes
・Beneficial to skin: Vitamin C can protect the skin from damage caused by free radicals. In addition, vitamin C can also promote the production of collagen, thus improving skin elasticity and luster. Vitamin C can also help the skin recover positively, reduce skin redness and pigment deposition. 

・Beneficial to eyes: Vitamin C can prevent the formation of free radicals in the eyes and prevent eye diseases. In addition, vitamin C can also promote the blood circulation in the eyes, prevent eye fatigue and dryness.

Sources of Vitamin C

Eat fresh fruits and vegetables, drink juices, and increase the intake of vitamin C supplements.

1.Food Sources
The top foods ranked by content are:

• Celery
• Green pepper
• Chili
• Kiwi
• Pistachio
• Pineapple
• Grapefruit
• Blackberry
• Red pepper
• Pomelo

The actual content may vary due to factors such as geographic location, season, storage and processing.

2.Supplement Sources
Vitamin C supplements are mainly found in pharmacies and nutrition stores and can be in the form of powders, tablets, liquids, etc. The appropriate dosage form needs to be selected according to one's own needs.

・Powder form: Vitamin C supplement in powder form can be conveniently added to drinks, food or water. In addition, vitamin C supplements in powder form can also conveniently adjust the dosage.

・Tablet form: Vitamin C supplement in tablet form is usually easy to take and can be used anywhere.

・Liquid form: Vitamin C supplement in liquid form is usually easy to absorb and can be taken directly.

Recommended Japanese Vitamin C Supplements

DHC Sustained Release Vitamin C：
DHC's Sustained Release Vitamin C is designed to enhance Vitamin C absorption with a time-release formula that gradually releases 1000mg of Vitamin C in the body, ensuring long-lasting effects. This formula provides continuous antioxidant protection, helping to combat free radicals, protect cells from oxidative damage, and support skin health and immune function, making it an effective supplement for maintaining beauty and overall well-being.

ORIHIRO Vitamin C：
"ORIHIRO Vitamin C 300 Tablets" is a nutritional supplement specifically formulated to support your daily Vitamin C needs. Each serving of 10 tablets delivers a potent dose of 1000mg of Vitamin C, making it easy to maintain optimal levels of this essential nutrient. Vitamin C is well-known for its powerful antioxidant properties, helping to protect the body from oxidative stress, support immune function, and promote healthy skin. This supplement is ideal for those looking to enhance their overall wellness by ensuring consistent and adequate Vitamin C intake in a convenient and effective way.

ITOH Kanpo Vitamin C Powder：
ITOH Japan's Vitamin C Powder offers a convenient way to boost your daily Vitamin C intake without the need for water. Unlike water-soluble Vitamin C that is quickly excreted from the body, this powder utilizes a unique slow-release granule technology, ensuring sustained absorption throughout the day. The powder has a natural lemon flavor, making it enjoyable to consume.Just one packet a day provides a full dose of revitalizing Vitamin C. For those who are using other beauty products, combining them with Vitamin C can further promote collagen production. This product is not only effective and affordable but also supports skin whitening. It's perfect to keep a box in the office for a quick and easy Vitamin C boost anytime, anywhere.

Side Effects, Safety and Recommended Intake of Vitamin C

Side Effects：
The side effects of vitamin C are usually mild, including diarrhea, bloating and stomach discomfort. These side effects are usually caused by excessive intake of vitamin C. Excessive intake of vitamin C can also lead to increased uric acid, thus increasing the risk of kidney stones.

Safety:
Vitamin C is a safe nutrient, widely considered to be safe. Normal supplement use will not cause toxic side effects, but excessive use of vitamin C may lead to adverse effects. Therefore, it is strongly recommended to consult a doctor or nutritionist before using supplements.

Recommended Intake:
The recommended intake of vitamin C is based on individual age, gender, physiological condition, lifestyle, etc.

• Healthy adults: The recommended intake is 75-90 mg per day.
• Pregnant women: Recommended intake is 85-120 mg.
• Breastfeeding women: Recommended intake is 115-120 mg.

For children, the recommended intake of vitamin C is as follows:

• 1-3 years old: 15 mg/day
• 4-8 years old: 25 mg/day
• 9-13 years old: 45 mg/day
• 14-18 years old: 65 mg/day

 Different countries and regions may also have different recommendations, and the specific needs to be determined according to the child's growth and development, lifestyle and other factors. It is recommended to consult a doctor or nutritionist for more accurate advice.