• Vitamin A is vital for a healthy immune system, bone growth, vision, cell recognition and reproduction. Vitamin A often works as an antioxidant, fighting cell damage, but it also has many other uses. It has a vital role in the formation of heart, lungs, and kidney.
• Other functions of vitamin A include the formation and maintenance of teeth, bones, soft tissue, white blood cells, the immune system and mucus membranes. 
• Most people get enough vitamin A from their diets. However, a doctor might suggest vitamin A supplements to people who have vitamin A deficiencies. People most likely to have vitamin A deficiency are those with diseases (such as digestive disorders) or very poor diets.

• Vitamin A is used for improving the eyesight, maintaining cells of the skin and the lining of the digestive, urinary and respiratory tracts.
• It also helps in the formation of red and white blood cells in our body that are important to carry out the various essential functions of our body.
• Topical and oral retinoids are common prescription treatments for acne and other skin conditions, including wrinkles. 
• Oral vitamin A is also used as a treatment for measles and dry eye in people with low levels of vitamin A. 
• Vitamin A is also used for a specific type of leukemia.
• Vitamin A has been studied as a treatment for many other conditions, including cancers, cataracts, and HIV. However, the results are inconclusive.

• Night blindness
• A higher risk of infections, especially in the throat, chest, and abdomen
• Follicular hyperkeratosis, leading to dry, bumpy skin.
• Fertility issues
• Delayed growth in children
• Symptoms of vitamin A toxicity include dry skin, joint pain, vomiting, headaches, confusion.

• If you take too much of Vitamin A, it can lead to birth defects, abnormalities of the liver and disorders of the central nervous system.
• It can also decrease bone mineral density, leading to an increased risk of osteoporosis.
• This is because an excess of Vitamin A suppresses the building up of bones and increases its breakdown.
• The rate of calcium absorption by Vitamin D can also get affected due to excess of Vitamin A. Therefore, it is advised to use Vitamin A only as directed by your doctor.
• Interactions. Vitamin A supplements may interact with some birth control pills, blood thinners (Coumadin), acne medicines (isotretinoin), cancer treatments, and many other drugs.
• People who drink heavily or have kidney or liver disease shouldn’t take vitamin A supplements without talking to a doctor.

Ascorbic acid (vitamin C) is a water-soluble vitamin. It occurs as a white or slightly yellow crystal or powder with a slight acidic taste. It is an antiscorbutic product. On exposure to light, it gradually darkens. In the dry state, it is reasonably stable in air, but in solution it rapidly oxidizes. Ascorbic acid (vitamin c) is freely soluble in water; sparingly soluble in alcohol; insoluble in chloroform, in ether, and in benzene. The chemical name of ascorbic acid (vitamin c) is L-ascorbic acid (vitamin c)

• Vitamin C is recommended for the prevention and treatment of scurvy.
• Symptoms of mild deficiency may include faulty bone and tooth development, gingivitis, bleeding gums, and loosened teeth. Febrile states, chronic illness, and infection (pneumonia, whooping cough, tuberculosis, diphtheria, sinusitis, rheumatic fever, etc.) increase the need for ascorbic acid (vitamin c).

Less common or rare- with high doses

•  Diarrhea
•  dizziness or faintness (with the injection only)
•  flushing or redness of skin
•  headache
•  increase in urination (mild)
•  nausea or vomiting
•  stomach cramps

• Diabetics, patients prone to recurrent renal calculi, those undergoing stool occult blood tests, and those on sodium-restricted diets or anticoagulant therapy should not take excessive doses of vitamin C over an extended period of time.
• Too-rapid intravenous injection is to be avoided.
• Diabetics taking more than 500 mg vitamin C daily may obtain false readings of their urinary glucose test.

Phenylalanine is used for depression, attention deficit-hyperactivity disorder (ADHD), Parkinson's disease, chronic pain, osteoarthritis, rheumatoid arthritis, alcohol withdrawal symptoms, and a skin disease called vitiligo.

Some people apply it directly to the skin for vitiligo

Phenylalanine is an amino acid, a "building block" of protein. L-phenylalanine is an essential amino acid and is the only form of phenylalanine found in proteins.

The amount of this amino acid found in foods should not pose a risk for otherwise healthy individuals.

This medicine can be consumed by pregnant and breastfeeding women unless absolutely necessary in a certain quantity.

 Phenylalanine should be avoided in people with certain inherited disorders that cause their bodies to build up too much phenylalanine.

People with this disorder can develop mental retardation, high blood pressure, stroke, and many other serious health issues if they consume phenylalanine. 

Lysine is an amino acid that acts as a building block for the protein in your body. This amino acid is essential since your body cannot produce it on its own.

• Our body’s need lysine to provide healthy functioning. Since lysine helps your body absorb calcium, it helps you treat anxiety.
• It plays a vital role in fighting diseases. Lysine helps the body produce infection-fighting antibodies, enzymes, hormones, and body tissues.
• Lysine supplements are sometimes used to treat a wide range of conditions, including Canker sores, Diabetes, High triglyceride levels, improved muscle strength and athletic performance, Bedsores, Schizophrenia.

• Diarrhoea
• Abdominal Pain
• Chronic Kidney (Renal) Failure
• Inflammation in the Kidney (Interstitial Nephritis)
• Increased Calcium Absorption

• Lysine supplements are possibly safe for most people when taken by mouth in appropriate doses for up to one year or when applied to the skin for up to one year.
• Certain people should avoid the supplement.
• There is not enough evidence to know if it is safe for women who are pregnant or breastfeeding.
• Also, those with kidney disease, intolerance to lysinuric protein, or osteoporosis should speak to their healthcare provider when taking the supplement.

The primary ingredient of L-Arginine is L-arginine, which is an amino acid present in the body. L-arginine plays an important role in many vital functions in the human body. 

 

L-arginine is a nonessential amino acid that may play an important role in the treatment of heart disease due to its block arterial plaque buildup, blood clots, platelet clumping, and to increase blood flow through the coronary artery. L- arginine is commonly sold as a health supplement claiming to improve vascular health and treat erectile dysfunction in men. L-arginine, which is promoted as a human growth stimulant, has also been used in bodybuilding

•  Abdominal pain
•  Difficulty in breathing
•  Allergic skin reaction
•  Low blood pressure
•  Low blood sugar levels
•  Diarrhea
•  Worsening of asthma
•  Bloating
•  Gout

• This supplement should be used with caution in patients with liver diseases due to the increased risk of severe adverse effects. 
• Regular monitoring of kidney function tests is necessary while receiving this supplement.
• This supplement is not recommended for use in patients who have recently undergone a surgery or are scheduled to undergo surgery in the near future due to the increased risk of alterations in the blood pressure levels. It is advised that you stop the use of this supplement at least 2 weeks prior to a scheduled surgery.
• This supplement is not recommended for use in patients suffering from a herpes infection due to the increased risk of worsening of the patient’s condition.

L-Histidine hydrochloride is the obligate precursor of histamine, which is produced via the decarboxylation of the amino acid. It may increase tissue histamine levels increase as the amount of dietary L-histidine increases. Histamine is known to possess immunomodulatory and antioxidant activity.

• Histidine is an α-amino acid that is used in the biosynthesis of proteins.
• It is used in the treatment of nutritional deficiencies.
• L-histidine may be indicated for use in some with rheumatoid arthritis.
• It is not indicated for the treatment of anaemia or uremia or for lowering serum cholesterol.

• Histidine might be safe for most people.
• Doses of up to 4 grams per day have been used in research without causing noticeable side effects.

• Pregnancy and breast-feeding: Not enough is known about the use of histidine during pregnancy and breast-feeding. Stay on the safe side and avoid use.
• Folic acid deficiency: If you have this condition, don't use histidine. It can cause an unwanted chemical called Formiminoglutamic Acid (FIGLU) to build up in the body.