The Vitamin Cure. Monte Lai
A can be used as an adjuvant therapy for treating blood cancers (45).
Which Food Items Are Vitamin A Rich?
Beef liver and fish liver oil contain high amounts of vitamin A. Milk and eggs are also excellent sources of vitamin A. Vegetables and fruits contain high levels of carotenoids.
This list of food items that are rich in vitamin A and beta-carotene is adapted from information provided by the USDA.
| FOODS | PORTION | VITAMIN A CONTENT, IU | % DAILY REFERENCE VALUE |
|---|---|---|---|
| Beef liver (cooked) | 1 slice (68 g) | 21,566 | 431 |
| Sweet potato (cooked) | ½ cup | 19,218 | 384 |
| Pumpkin (cooked) | ½ cup | 19,065 | 381 |
| Carrots (raw) | ½ cup | 10,692 | 214 |
| Spinach (cooked) | ½ cup | 9,433 | 214 |
| Cantaloupe | ½ | 9,334 | 187 |
| Mango | 1 | 3,636 | 73 |
| Broccoli (cooked) | ½ cup | 1,207 | 24 |
| Milk | 1 cup | 395 | 8 |
| Eggs | 1 | 270 | 5 |
Daily reference value of vitamin A is 5,000 IU according to the 2013 FDA food-labeling guidelines.
How to Calculate the Dosage of Vitamin A
International Units (IU) are commonly used to quantify vitamin A in food items and supplements.
• 1 IU of vitamin A is equal to 0.3 mcg of retinol
• 1 IU of beta-carotene is equal to 0.15 mcg of retinol
• 1 IU of beta-carotene in food is equal to 0.025 mcg of retinol
What Are the Recommended Dietary Allowances for Vitamin A?
| 1–3 years | 1,000 IU |
| 4–8 years | 1,333 IU |
| 9–13 years | 2,000 IU |
| 14 years and older | 3,000 IU (men); 2,333 IU (women) |
The upper daily intake limit of vitamin A is 10,000 IU.
Vitamin A Supplements
• Dosage. The common dosage for vitamin A supplements ranges from 5,000 to 25,000 IU. Vitamin A supplements can be taken either daily or weekly. The recommended dose is 3,000 IU daily or 20,000 IU weekly.
• Types. Vitamin A supplements are mainly composed of retinol, retinyl acetate, and retinyl palmitate. Their weight-to-unit conversion factors are as follows:◦ 0.3 mcg of retinol is equal to 1 IU of vitamin A◦ 0.344 mcg of retinyl acetate is equal to 1 IU of vitamin A◦ 0.55 mcg of retinyl palmitate is equal to 1 IU of vitamin A
• Fish liver oil. Fish liver oil contains vitamin A, vitamin D, and omega-3 fatty acids, including EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). There are two types of fish liver oil supplements: regular and fermented. Fermented fish liver oil supplements are more expensive compared to regular fish liver oil supplements. The fermentation process enhances the contents and purity of vitamin A, vitamin D, and the omega-3 fatty acids. The vitamin A in fish liver oil is a natural retinyl palmitate, which is the same as synthetic retinyl palmitate.
• Melanoma. Vitamin A can prevent melanoma. Clinical studies have shown that taking a dose of 4,000 IU of vitamin A daily for six months reduced the risk of melanoma by 40%. The protective effect was more profound in women than in men.
• Wrinkles. Vitamin A reduces wrinkles, making older skin look younger. Topical vitamin A at a dose of 0.4% applied three times weekly was effective in reducing wrinkles within weeks.
Safety Issues
• Overdose. Long-term consumption of high doses of vitamin A may cause hypervitaminosis A. Symptoms include blurred vision, lack of appetite, dry skin, and muscle weakness. High doses of vitamin A can cause liver damage as well as osteoporosis.
• Pregnant women. During pregnancy, women should take no more than 25,000 IU of vitamin A supplement daily to avoid hypervitaminosis A, which can lead to birth defects in infants.
• Recommended daily dose. Vitamin A is lipid-soluble and, once absorbed, will be retained in the body for a long time. It is recommended that you take no more than 10,000 IU of vitamin A per day.
What Types of Drugs May Interact with Vitamin A?
• Alcohol can exacerbate liver damage caused by high doses of vitamin A. Drinking alcoholic beverages with beef liver slices as a side dish is prevalent in some Asian cultures, which can lead to vitamin A toxicity. Furthermore, cholesterol-lowering drugs that hinder lipid absorption may also diminish vitamin A absorption.
• Long-term consumption of high doses of vitamin A can decrease vitamin K absorption, leading to vitamin K deficiency. Vitamin A enhances the drug action of warfarin. People who take warfarin to treat and prevent blood clots together with high-dose vitamin A should consult with health-care professionals.
Thiamine was the first B vitamin discovered; therefore, it was named vitamin B1. Vitamin B1 deficiency leads to beriberi disease. In 2600 BCE, ancient Chinese writings recorded the prevalence of beriberi disease in China. Dutch physicians in the 19th century noted that chickens fed only polished rice developed paralysis. Certain important nutrients seemed to be missing from polished rice. In the early 20th century, Casimir Funk isolated a water-soluble antineuritic substance from bran, the hard outer layer of cereal grain, and demonstrated that it could treat beriberi disease. He named the antineuritic substance “vitamine.” Vita in Latin means “life,” so a “vitamine” is required for life and was originally thought to be an amine.
Vitamin B1 obtained from foods is stored mostly