protein, reducing inflammation and the risk of cardiovascular diseases.
• Asthma. Vitamin D supplementation can alleviate pulmonary inflammation, enhance lung function, and control asthma. Supplementation with vitamin D can enhance the efficacy of inhaled corticosteroids in asthmatic patients. The suggested daily dose is 800 IU.
• Chronic obstructive pulmonary disease. Supplementation with vitamin D can mitigate symptoms of chronic obstructive pulmonary disease. The suggested daily dose is 2,000 IU.
• Childhood allergies. Children and teenagers whose blood levels of vitamin D are below 15 ng/ml have an increased risk of developing childhood allergies. When pregnant women take vitamin D supplements at a daily dose of 800 IU during the last three months of pregnancy, it reduces the risk of childhood allergies in their babies.
• Fibromyalgia. Fibromyalgia is a chronic disease characterized by diffuse or sharp pain in joints and muscles. Studies from Austria have shown that supplementation with vitamin D improved symptoms of fibromyalgia in patients. The suggested daily dose is 1,200 IU of vitamin D.
• Lupus erythematosus. Vitamin D supplementation can improve symptoms in patients with lupus erythematosus. Adding vitamin D to prescribed medications alleviates the frequency of relapses and enhances immune functions in patients with lupus erythematosus.
• Depression. Low blood levels of vitamin D increase the risk of depression in elderly individuals. Supplementation with vitamin D can alleviate depression symptoms in type 2 diabetes patients as well.
• Dementia. Elderly individuals whose blood levels of vitamin D are below 10 ng/ml have a greater risk of dementia and Alzheimer’s disease. Supplementation with vitamin D at a dose of 500 IU reduces the risk of Alzheimer’s disease by 77%. Elderly individuals whose blood levels of vitamin D are higher than 20 ng/ml decrease their risk of Parkinson’s disease by 60%.
• Cancers. Low blood levels of vitamin D put you at a higher risk of colorectal cancer, breast cancer, melanoma, bladder cancer, and lung cancer. Supplementation with vitamin D improves symptoms of cancer as well as survival rates. The suggested daily dose is 800 IU of vitamin D3.
• Other diseases. Low blood levels of vitamin D heighten the risk of rheumatoid arthritis, heart disease, hypertension, and coronary artery disease, shortening life expectancy overall.
Safety Issues
• Side effects. Excessive vitamin D can cause hypercalcemia, leading to the formation of kidney stones. Avoid taking more than 10,000 IU of vitamin D per day.
• Lipids. Lipids increase the absorption of vitamin D by the intestines. Select a meal with a higher fat content when you are taking vitamin D supplements.
What Types of Drugs May Interact with Vitamin D?
• Anticonvulsant medications, cholesterol-lowering drugs, and chemotherapy can reduce blood levels of vitamin D.
Vitamin E is also known as alpha-tocopherol. In 1922, Herbert Evans studied infertility by feeding rats with his specially formulated feeds. Rats fed with the feeds looked healthy, except pregnant rats. All new broods were dead in the womb. Evans found that by adding vegetables to the feeds, pregnant rats gave birth to healthy broods. He called the lipid-soluble substance isolated from vegetables “factor X.” In 1924, Barnett Sure, who also worked on infertility, renamed it vitamin E. In 1936, Evans confirmed that the chemical structure of vitamin E was alpha-tocopherol. Tocopherol came from Greek tokos, meaning “offspring,” and pherin, meaning “pregnancy.”
Vitamin E from plants consists of eight structurally related chemicals. Among them, alpha-tocopherol is the most important to human health. The lipid-soluble vitamin E is known as a chain-breaking antioxidant. Vitamin E from foods is absorbed in the intestines and distributed through blood circulation to all the cells in the body. In the cellular membrane, vitamin E acts like a guard to get rid of free radicals and prevent free radical–induced chain reactions. Free radicals and other reactive oxygen species can initiate chain reactions that cause oxidative damage to phospholipids and proteins in the cellular membrane, leading to cell death. Vitamin E can terminate this chain reaction.
What Are the Major Functions of Vitamin E?
• Antioxidant. Lipid-rich cellular organelles and molecules—such as cell membranes, LDL, and HDL—are susceptible to free radical–induced lipid peroxidation and other related oxidative damage. Lipid-soluble vitamin E can quench free radicals and prevent the lipid peroxidation of cell membranes and molecules in the lipid-rich cellular environment.
What Are the Symptoms of Vitamin E Deficiency?
• Severe vitamin E deficiency is rare. Deficiency symptoms include the inability to stand still, numbness in the extremities, muscle pain and cramps, and retinal malfunction.
• Low blood levels of vitamin E are associated with peripheral neuropathy, ataxia (uncontrollable muscle movement), and retinitis pigmentosa (hereditary retinal degeneration).
Prevention and Treatment of Diseases
• Prevention. Meta-analysis confirms that vitamin E can help prevent breast cancer (47), lung cancer (82), renal cell cancer (100), bladder cancer (44), stomach cancer (107), pancreatic cancer (95), prostate cancer (99), cervical cancer (50), endometrial cancer (63), Alzheimer’s disease (37), Parkinson’s disease (96), fatty liver disease (66), cardiovascular disease (48), heart disease (73), and cataracts (49).
• Treatment. Meta-analysis confirms that vitamin E can treat fatty liver disease (66).
Which Food Items Are Vitamin E Rich?
Vitamin E comes from plant-based foods. Vegetable oils—such as wheat germ oil, peanut oil, almond oil, and sunflower oil—are excellent sources of vitamin E. Many vegetables and fruits are also rich in vitamin E, such as asparagus, sweet potatoes, avocados, mangos, and nuts.
This list of vitamin E–rich food items is adapted from information provided by the NIH Office of Dietary Supplements.
| FOOD | PORTION | VITAMIN E CONTENT, IU | % DAILY REFERENCE VALUE |
|---|---|---|---|
| Almond | 1 ounce | 15.0 | 50 |
| Sunflower oil | 1 teaspoon | 12.4 | 41 |
| Safflower oil | 1 teaspoon |
