Your Nutrients

Acetyl-L-carnitine is similar in form to the amino acid L-carnitine and also has some similar functions, such as being involved in the metabolism of food into energy. The acetyl group that is part of acetyl-L-carnitine contributes to the production of the neurotransmitter acetylcholine, which is required for mental function.

Acetyl-L-carnitine is a molecule that occurs naturally in the brain, liver, and kidney. It is also available as a dietary supplement.

Acetyl-L-carnitine levels may decrease with advancing age. However, because it is not an essential nutrient, true deficiencies do not occur.

Age-related cognitive decline Alzheimer’s disease Cerebellar ataxia, degenerative Depression (for elderly people) Down’s syndrome Erectile dysfunction (in combination with L-carnitine) Macular degeneration (in combination with fish oil and coenzyme Q10) Type 1 diabetes Type 2 diabetes Amenorrhea Male infertility Peripheral neuropathy

Side effects from taking acetyl-L-carnitine are uncommon, although skin rash, increased appetite, nausea, vomiting, agitation, and body odor have been reported in people taking acetyl-L-carnitine. Certain medicines may interact with acetyl-L-carnitine. Refer to drug interactions for a list of those medicines.

Most research involving acetyl-L-carnitine has used 500 mg three times per day, though some research has used double this amount.

Folic acid is a B vitamin needed for cell replication and growth. Folic acid helps form building blocks of DNA, the body’s genetic information, and building blocks of RNA, needed for protein synthesis in all cells. Therefore, rapidly growing tissues, such as those of a fetus, and rapidly regenerating cells, like red blood cells and immune cells, have a high need for folic acid. Folic acid deficiency results in a form of anemia that responds quickly to folic acid supplementation.

Beans, leafy green vegetables, citrus fruits, beets, wheat germ, and meat are good sources of folic acid.

Many people consume less than the recommended amount of folic acid. Scientists have found that people with heart disease commonly have elevated blood levels of homocysteine, a laboratory test abnormality often controllable with folic acid supplements. This suggests that many people in Western societies have a mild folic acid deficiency. In fact, it has been suggested that increasing folic acid intake could prevent an estimated 13,500 deaths from cardiovascular diseases each year. Folic acid deficiency has also been common in alcoholics, people living at poverty level, those with malabsorption disorders or liver disease (e.g., cirrhosis), and women taking the birth control pill. Recently, elderly people with hearing loss have been reported to be much more likely to be folic acid deficient than healthy elderly people. A variety of prescription drugs including cimetidine, antacids, some anticancer drugs, triamterene, sulfasalazine, and anticonvulsants interfere with folic acid. Deficiency of folic acid can be precipitated by situations wherein the body requires greater than normal amounts of the vitamin, such as pregnancy, infancy, leukemia, exfoliative dermatitis, and diseases that cause the destruction of blood cells. The relationship between folic acid and prevention of neural tube defects is partly thought to result from the high incidence of folate deficiency in many societies. To protect against neural tube defects, the U.S. Food and Drug Administration has mandated that some grain products provide supplemental folic acid at a level expected to increase the dietary intake by an average of 100 mcg per day per person. As a result of folic acid added to the food supply, fewer Americans will be depleted compared with the past. In 1999, scientific evidence began to demonstrate that the folic acid added to the U.S. food supply was having positive effects, including a partial lowering of homocysteine levels. In the same year, however, a report from the North Carolina Birth Defects Monitoring Program suggested the current level of folic acid fortification has not reduced the incidence of neural-tube defects. Many doctors and the Centers for Disease Control in Atlanta believe that optimal levels of folic acid intake may still be higher than the amount now being added to food by several hundred micrograms per day. A low blood level of folate has also been associated with an increased risk of miscarriage. People with kidney failure have an increased risk of folic acid deficiency. Recipients of kidney transplants often have elevated homocysteine levels, which may respond to supplementation with folic acid. The usual recommended amount of 400 mcg per day may not be enough for these people, however. Larger amounts (up to 2.4 mg per day) may produce a better outcome, according to one double-blind trial. Folate deficiency is more prevalent among elderly African American women than among elderly white women.

Birth defects prevention Depression Gingivitis (periodontal disease) (rinse only) High homocysteine (in combination with vitamin B6 and vitamin B12) Pap smear (abnormal) (in women taking oral contraceptives) Pregnancy and postpartum support Schizophrenia (for deficiency) Anemia (for thalassemia if deficient) Atherosclerosis Breast cancer (reduces risk in women who consume alcohol) Canker sores (for deficiency only) Celiac disease (for deficiency only) Colon cancer (prevention) Heart attack Preeclampsia Sickle cell anemia (for lowering homocysteine levels) Skin ulcers Ulcerative colitis Alzheimer’s disease Bipolar Disorder/Manic Depression Crohn’s disease Dermatitis herpetiformis (for deficiency) Diarrhea Down’s syndrome Epilepsy Gingivitis (periodontal disease) (pill) Gout HIV support Lung cancer (reduces risk) Osteoporosis Peripheral vascular disease Psoriasis Restless legs syndrome Seborrheic dermatitis Stroke (for high homocysteine only) Vitiligo

Folic acid is not generally associated with side effects. However, folic acid supplementation can interfere with the laboratory diagnosis of vitamin B12 deficiency, possibly allowing the deficiency to progress undetected to the point of irreversible nerve damage. Although vitamin B12 deficiency is uncommon, no one should supplement with 1,000 mcg or more of folic acid without consulting a doctor. Vitamin B12 deficiencies often occur without anemia (even in people who do not take folic acid supplements). Some doctors do not know that the absence of anemia does not rule out a B12 deficiency. If this confusion delays diagnosis of a vitamin B12 deficiency, the patient could be injured, sometimes permanently. This problem is rare and should not happen with doctors knowledgeable in this area using correct testing procedures. Folic acid is needed by the body to utilize vitamin B12. Proteolytic enzymes inhibit folic acid absorption. People taking proteolytic enzymes are advised to supplement with folic acid. Certain medicines may interact with folic acid. Refer to drug interactions for a list of those medicines.

Many doctors recommend that all women who are or who could become pregnant take 400 mcg per day in order to reduce the risk of birth defects. Some doctors also extend this recommendation to other people in an attempt to reduce the risk of heart disease by lowering homocysteine levels. Since the FDA mandated addition of folic acid to grain products, many people who eat grains have followed the new recommendation of supplementing only 100 mcg of folic acid per day. However, studies have found that this amount of folic acid is inadequate to maintain normal folate levels in a significant percentage of the groups assessed. It now appears that, for pregnant women, supplementing with at least 300 mcg (and optimally 400 mcg) of folic acid per day is sufficient to prevent a folate deficiency, even if dietary intake is low.

5-HTP is used by the human body to make serotonin, an important substance for normal nerve and brain function. Serotonin appears to play significant roles in sleep, emotional moods, pain control, inflammation, intestinal peristalsis, and other body functions.

5-HTP is not present in significant amounts in a typical diet. The human body manufactures 5-HTP from L-tryptophan, a natural amino acid found in most dietary proteins. However, eating food that contains L-tryptophan does not significantly increase 5-HTP levels. Supplemental 5-HTP is naturally derived from the seeds of Griffonia simplicifolia, a West African medicinal plant.

Disruptions in emotional well-being, including depression and anxiety, have been linked to serotonin imbalances in the brain. People with fibromyalgia often have low serotonin levels in their blood. Supplements of 5-HTP may increase serotonin synthesis in these cases. The cause of migraine headaches is related to abnormal serotonin function in blood vessels, and 5-HTP may help correct this abnormality. Insomnia has been associated with tryptophan deficiency in the tissues of the brain; therefore, 5-HTP may provide a remedy for this condition.

Depression Fibromyalgia Insomnia Migraine headaches Sleep terrors Tension headache Weight loss and obesity Bipolar disorder/manic depression Eating disorders Parkinson’s disease (with Sinemet®) Seasonal affective disorder

During the clinical trials described above, some people taking large amounts of 5-HTP experienced gastrointestinal upset (e.g. nausea) or, less often, headache, sleepiness, muscle pain, or anxiety. A substance known as “Peak X” has been found in low concentrations in several over-the-counter 5-HTP preparations. Some researchers think this substance may be linked to toxicity previously reported in a 1989 L-tryptophan contamination incident. However, there is serious question about whether Peak X is actually the toxic agent and it may be unrelated to the problems previously associated with L-tryptophan. Although two articles reported possible associations between 5-HTP consumption and toxicity symptoms similar to those attributed to contaminated L-tryprophan, evidence linking 5-HTP or Peak X with any toxicity symptoms remains speculative. Although the structure of Peak X has recently been identified, there is no firm evidence that this substance has caused or contributed to any toxicity or disease. Very high intakes of 5-HTP have caused muscle jerks in guinea pigs and both muscle jerks and diarrhea in mice. Injected 5-HTP has also caused kidney damage in rats. To date, these problems have not been reported in humans. “Serotonin syndrome,” a serious but uncommon condition caused by excessive amounts of serotonin, has not been reported to result from supplementation with 5-HTP; in theory it could be triggered by the supplement. However, the level of intake at which this toxic effect might potentially occur remains unknown. 5-HTP should not be taken with antidepressants, weight-control drugs, other serotonin-modifying agents, or substances known to cause liver damage, because in these cases 5-HTP may have excessive effects. People with liver disease may not be able to regulate 5-HTP adequately and those suffering from autoimmune diseases such as scleroderma may be more sensitive than others, to 5-HTP. These people should not take 5-HTP without consulting a knowledgeable healthcare professional. The safety of taking 5-HTP during pregnancy and breast-feeding is not known at this time. Certain medicines may interact with 5-hydroxytryptophan. Refer to drug interactions for a list of those medicines.

In a controlled trial, 5-HTP (300 mg per day) was shown to be effective in reducing many symptoms of fibromyalgia, including pain, morning stiffness, sleep disturbances, and anxiety. For depression, 300 mg per day is often effective, though much of the research used 5-HTP in combination with drugs or was uncontrolled. For insomnia, a single 100-mg nighttime dose of 5-HTP was sufficient to improve the duration and depth of sleep in one placebo-controlled trial. For migraine headaches, amounts ranging from 400–600 mg per day have been shown to be effective at reducing the frequency and severity of attacks in most clinical trials. For tension headaches, 100 mg of 5-HTP taken three times per day led to a significant decrease in consumption of pain-relievers, but no significant change in headache duration or intensity. Appetite reduction and weight loss (averaging 11 pounds in 12 weeks) has occurred with amounts of 600–900 mg daily. In another clinical trial, 750 mg per day has been shown to be effective at decreasing carbohydrate and fat intake, and promoting weight loss.

Menopause (in combination with sage) High cholesterol Menopause Poor appetite

Use of the dried leaves of alfalfa in the amounts listed above is usually safe. There have been isolated reports of people who are allergic to alfalfa. Ingestion of very large amounts (the equivalent of several servings) of the seed and/or sprouts has been linked to the onset of systemic lupus erythematosus (SLE) in animal studies. It has also been linked to the reactivation of SLE in people consuming alfalfa tablets. SLE is an autoimmune illness characterized by inflamed joints and a high risk of damage to kidneys and other organs. The chemical responsible for this effect is believed to be canavanine. At the time of writing, there were no well-known drug interactions with alfalfa.

Dried alfalfa leaf is available as a bulk herb, and in tablets or capsules. It is also available in liquid extracts. No therapeutic amount of alfalfa has been established for humans. Some herbalists recommend 500–1,000 mg of the dried leaf per day or 1–2 ml of tincture three times per day.

Flavonoids are a class of water-soluble plant pigments. Flavonoids are broken down into categories, though the issue of how to divide them is not universally agreed upon. One system breaks flavonoids into isoflavones, anthocyanidins, flavans, flavonols, flavones, and flavanones. Some of the best-known flavonoids, such as genistein in soy, and quercetin in onions, can be considered subcategories of categories. Although they are all structurally related, their functions are different. Flavonoids also include hesperidin, rutin, citrus flavonoids, and a variety of other supplements.

Flavonoids are found in a wide range of foods. For example, flavanones are in citrus, isoflavones in soy products, anthocyanidins in wine and bilberry, and flavans in apples and tea.

Flavonoid deficiencies have not been reported.

Chronic venous insufficiency (rutin) Edema (water retention) (coumarin, hydroxyethylrutosides) Hepatitis (catechin) Bruising Cold sores Diabetes (bilberry) Dysmenorrhea (rutin plus vitamin B3 [niacin] and vitamin C) Edema (water retention) (diosmin and hesperidin combination) Gingivitis (periodontal disease) (in combination with vitamin C) Hemorrhoids (hydroxyethylrutosides derived from rutin) Ménière’s disease (hydroxyethylrutosides) Retinopathy (bilberry) Skin ulcers (diosmin, hesperidin) Allergies Atherosclerosis (quercetin, bilberry) Cancer (naringenin) Capillary fragility (hesperidin, quercetin, rutin) Cataracts (quercetin, bilberry) Diabetes (quercetin) Edema (water retention) (quercetin) Gingivitis (periodontal disease) Glaucoma (rutin) Hay fever (quercetin, hesperidin, rutin) Macular degeneration (bilberry) Measles Menopause (hesperidin) Menorrhagia (heavy menstruation) Night blindness (bilberry) Peptic ulcer (quercetin) Progressive pigmented purpura (in combination with vitamin C) Retinopathy (quercetin, rutin)

No consistent side effects have been linked to the flavonoids except for catechin, which can occasionally cause fever, anemia from breakdown of red blood cells, and hives. These side effects subsided when treatment was discontinued. In 1980, quercetin was reported to induce cancer in animals. Most further research did not find this to be true, however. While quercetin is mutagenic in test tube studies, it does not appear to be mutagenic in animal studies. In fact, quercetin has been found to inhibit both tumor promoters and human cancer cells. People who eat high levels of flavonoids have been found to have an overall lower risk of getting a wide variety of cancers, though preliminary human research studying only foods high in quercetin has found no relation to cancer risk one way or the other. Despite the confusion, in recent years experts have shifted their view of quercetin from concerns that it might cause cancer in test tube studies to guarded hope that quercetin has anticancer effects in humans. The flavonoids work in conjunction with vitamin C. Citrus flavonoids, in particular, improve the absorption of vitamin C. Certain medicines may interact with flavonoids. Refer to drug interactions for a list of those medicines.

Flavonoid supplements are not required to prevent deficiencies in people eating a healthy diet. Healthcare practitioners commonly recommend 1,000 mg of citrus flavonoids taken one to three times per day. Alternatively, 240–600 mg of bilberry (standardized to 25% anthcyanosides) may be taken per day.

L-phenylalanine (LPA) serves as a building block for the various proteins that are produced in the body. LPA can be converted to L-tyrosine (another amino acid) and subsequently to L-dopa, norepinephrine, and epinephrine. LPA can also be converted (through a separate pathway) to phenylethylamine, a substance that occurs naturally in the brain and appears to elevate mood.

LPA is found in most foods that contain protein. DPA does not normally occur in food. However, when phenylalanine is synthesized in the laboratory, half appears in the L-form and the other half in the D-form. These two compounds can also be synthesized individually, but it is more expensive to do so. The combination supplement (DLPA) is often used because of the lower cost and because both components exert different health-enhancing effects.

People whose diets are very low in protein may develop a deficiency of LPA, although this is believed to be very uncommon. However, one does not necessarily have to be deficient in LPA in order to benefit from a DLPA supplement.

Depression (DPA, LPA, DLPA) Low back pain (DPA) Pain (DPA) Parkinson’s disease (DPA) Vitiligo (LPA) Alcohol withdrawal support (DLPA) Osteoarthritis (DPA) Rheumatoid arthritis (DPA)

The maximum amount of DLPA that is safe is unknown. However, consistent toxicity in healthy people has not been reported with 1,500 mg per day or less of DLPA, except for occasional nausea, heartburn, or transient headaches. When 100 mg of LPA per 2.2 pounds body weight or more was given to animals, a variety of complex problems occurred, leading two researchers to have concerns about potential toxicity of high amounts in humans. While these concerns were directed at LPA specifically, they are likely to be equally applicable to DLPA. Although no serious adverse effects have been reported in humans taking phenylalanine, amounts greater than 1,500 mg per day should be supervised by a doctor. People with phenylketonuria must not supplement with phenylalanine. Some research suggests that people with tardive dyskinesia may process phenylalanine abnormally. Until more is known, it makes sense for people with this condition to avoid phenylalanine supplementation. LPA competes with several other amino acids for uptake into the body and the brain. Therefore, for best results, phenylalanine should be taken between meals, or away from protein-containing foods. People taking prescription or over-the-counter medications should consult a physician before taking DLPA. At the time of writing, there were no well-known drug interactions with phenylalanine.

DLPA has been used in amounts ranging from 75–1,500 mg per day. This compound can have powerful effects on mood and on the nervous system, and therefore DLPA should be taken only under medical supervision. LPA has been used in amounts up to 3.5 grams per day. For best results, phenylalanine should be taken between meals, because the protein present in food can interfere with the uptake of phenylalanine into the brain, potentially reducing its effect.

Boron is a nonmetallic element present in the diet and in the human body in trace amounts. Whether boron is an essential nutrient for humans remains in debate.

Raisins, prunes, and nuts are generally excellent sources of boron. Fruit (other than citrus), vegetables, and legumes also typically contain significant amounts. Actual amounts vary widely, depending upon boron levels in soil where the food is grown.

As boron is not yet considered an essential nutrient for humans, it is not clear whether deficiencies occur. However, diets that are low in fruit, vegetables, legumes, and nuts provide less boron than diets that contain more of these foods.

Osteoarthritis Osteoporosis Rheumatoid arthritis

Accidental acute exposure to high levels of boron can cause nausea, vomiting, abdominal pain, rash, convulsions, and other symptoms. Although chronic exposures can cause related problems, the small (usually 1–3 mg per day) amounts found in supplements have not been linked with toxicity in most reports. Nonetheless, in one double-blind trial using 2.5 mg of boron per day for two months, hot flashes and night sweats worsened in 21 of 43 women, though the same symptoms improved in 10 others. Women whose have hot flashes or night sweats have been diagnosed as menopausal symptoms and who supplement with boron should consider discontinuing use of boron-containing supplements to see if the severity of their symptoms is reduced. One study found that 3 mg per day resulted in increased estrogen and testosterone levels. Increased estrogen has also been reported in several women taking 2.5 mg per day. The increase in estrogen is of concern because it could theoretically increase the risk of several cancers. Although no increased risk of cancer has been reported in areas of the world where boron intake is high, some doctors recommend that supplemental boron intake be limited to a maximum of 1 mg per day. The relationship between boron and other minerals is complex and remains poorly understood. Boron may conserve the body’s use of calcium, magnesium, and vitamin D. In one study, the ability of boron to reduce urinary loss of calcium disappeared when subjects were also given magnesium. Therefore, boron may provide no special benefit in maintaining bone mass in the presence of adequate amounts of dietary magnesium. At the time of writing, there were no well-known drug interactions with boron.

A leading boron expert has suggested 1 mg per day of boron is a reasonable amount to consume. People who eat adequate amounts of produce, nuts, and legumes are likely already eating two to six times this amount. Therefore, whether the average person would benefit by supplementing with this mineral remains unclear.

Kelp is a sea vegetable that is a concentrated source of minerals, including iodine, potassium, magnesium, calcium, and iron. Kelp as a source of iodine assists in making thyroid hormones, which are necessary for maintaining normal metabolism in all cells of the body.

Kelp can be one of several brown-colored seaweed species called Laminaria.

People who avoid sea vegetables, as well as dairy, seafood, processed food, and the salt shaker, can become deficient in iodine. Iodine deficiency can cause low thyroid function, goiter, and cretinism. Although iodine deficiency is now uncommon in Western societies, the U.S. population has shown a trend of significantly decreasing iodine intake.

Iodine deficiency

There have been several case reports of high intakes of kelp providing too much iodine and interfering with normal thyroid function. People with thyroid disease should check with a doctor before taking supplements that contain kelp. At the time of writing, there were no well-known drug interactions with kelp.

Since the introduction of iodized salt, additional sources of iodine, such as kelp, are not necessary for most people. However, kelp can be consumed as a source of other minerals. A report from Great Britain indicated that the average kelp-based supplement contained 1,000 mcg of iodine (the adult RDA in the United States is 150 mcg per day). It has been suggested that intakes above 2,000 mcg per day should be regarded as excessive or potentially harmful.

Gamma oryzanol is a naturally occurring mixture of plant chemicals called sterols and ferulic acid esters.

Gamma oryzanol is a natural component of rice bran, corn, and barley oils. Gamma oryzanol is also available as a supplement.

Since gamma oryzanol is not an essential nutrient, it is not associated with a deficiency state.

Gastritis Athletic performance

Some research suggests that gamma oryzanol taken in moderately high amounts (up to 600 mg per day) for several months can cause dry mouth, sleepiness, hot flushes, irritability, and light headedness in some individuals. At the time of writing, there were no well-known drug interactions with gamma oryzanol.

Much of the human research with gamma oryzanol used 300 mg per day. Healthy people do not appear to need this supplement.

Strontium is a mineral that is not classified as essential for the human body.

Strontium is widely distributed throughout nature. Strontium levels in the soil determine how much strontium will be in the foods grown in particular areas. Areas with strontium-rich soils also tend to have higher levels of strontium in the drinking water.

Strontium is not an essential mineral, so deficiencies are not seen with this mineral.

Osteoporosis Dental cavities

No consistent toxicities from strontium supplements have been reported. At the time of writing, there were no well-known drug interactions with strontium.

No recommended intake levels have been established for strontium, since it is not considered essential for humans. However, preliminary research in humans suggests that 600–1,700 mg of strontium, taken as a supplement in the form of strontium salts, may increase bone mass in the vertebrae of people with osteoporosis.