What is vitamin C?
Vitamin C (also known as ascorbic acid) is abundant in vegetables and fruits. A water-soluble vitamin and powerful antioxidant, it helps the body form and maintain connective tissue, including bones, blood vessels, and skin.
What does vitamin C do? What are some vitamin C benefits?
Vitamin C helps to repair and regenerate tissues, protect against heart disease, aid in the absorption of iron, prevent scurvy, and decrease total and LDL (“bad”) cholesterol
and triglycerides. Research indicates that vitamin C may help protect
against a variety of cancers by combating free radicals, and helping
neutralize the effects of nitrites (preservatives found in some packaged
foods that may raise the risk of certain forms of cancer). Supplemental
vitamin C may also lessen the duration and symptoms of a common cold,
help delay or prevent cataracts, and support healthy immune function.
What are the signs of a vitamin C deficiency?
Deficiency symptoms include fatigue, muscle weakness, joint and
muscle aches, bleeding gums, and leg rashes. Prolonged deficiency can
cause scurvy, a rare but potentially severe illness.
How much, and what kind, does an adult need?
According to the National Institutes of Health (NIH), the recommended vitamin C daily allowance (RDA) for adults over age 19 is:
- men, 90 mg per day
- women, 75 mg per day
- pregnant women, 85 mg per day
- breastfeeding women, 120 mg per day.
Smokers may benefit from a higher intake. Dr. Weil recommends taking 250 mg of vitamin C each day.
How much does a child need?
NIH recommends Adequate Intakes (AIs):
- infants 0-6 months old, 40 mg per day
- infants 7-12 months old, 50 mg per day.
The RDAs of vitamin C for teens and children are:
- toddlers 1-3 years old, 15 mg per day
- children 4-8 years old, 25 mg per day
- children 9-13 years old, 45 mg per day
- male teens 14-18 years old, 75 mg per day
- female teens 14-18 years old, 65 mg per day
How do you get enough vitamin C from foods?
Vitamin C is easy to get through foods, as many fruits and vegetables
contain vitamin C. Good sources include: apples, asparagus, berries,
broccoli, cabbage, melon (cantaloupe, honeydew, watermelon),
cauliflower, citrus fruits (lemons, limes, oranges), kiwi, fortified
foods (breads, grains, cereal), dark leafy greens (kale, spinach),
peppers (especially red bell peppers, which have among the highest
per-serving vitamin C content), potatoes, and tomatoes.
Are there any risks associated with too much vitamin C?
When obtained from food sources and supplements in the recommended
dosages, vitamin C is generally regarded as safe. Side effects are
rarely reported, but include diarrhea, nausea, abdominal cramps, and
other gastrointestinal symptoms. For most healthy individuals, the body
can only hold and use about 200-250 mg of vitamin C a day, and any
excess is lost though urine. At times of illness, during recovery from
injury, or under conditions of increased oxidative stress (including
smoking), the body can use greater amounts. High doses of vitamin C
(greater than 2,000 mg/day) may contribute to the formation of kidney stones, as well as cause severe diarrhea, nausea, and gastritis.
Are there any other special considerations?
Adverse affects may occur between vitamin C and anticoagulant drugs
such as warfarin (Coumadin), decreasing their action. Nicotine products,
oral contraceptives/estrogens, tetracyclines, barbiturates, and aspirin
may decrease levels of vitamin C.
Vitamin C may increase absorption of iron and lutein. Although some
evidence suggests that large doses of supplemental vitamin C may
interfere with the absorption and metabolism of vitamin B12 found in food, other studies have shown no such effects.
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