Treatment of LPLD has two different objectives: immediate prevention of pancreatitis attacks and long term reduction of cardiovascular disease risk. Treatment is mainly based on medical nutrition therapy to maintain plasma triglyceride concentration below 11,3 mmol/L (1000 mg/dL). Maintenance of triglyceride levels below 22,6 mmol/L (2000 mg/dL) prevents in general from recurrent abdominal pain.

Strict low fat diet and avoidance of simple carbohydrates

Restriction of dietary fat to not more than 20 g/day or 15% of the total energy intake is usually sufficient to reduce plasma triglyceride concentration, although many patients report that to be symptom free a limit of less than 10g/day is optimal. Simple carbohydrates should be avoided as well. Medium-chain triglycerides can be used for cooking, because they are absorbed into the portal vein without becoming incorporated into chylomicrons. Fat-soluble vitamins A, D, E, and K, and minerals should be supplemented in patients with recurrent pancreatitis since they often have deficiencies as a result of malabsorption of fat. However, the diet approach is difficult to sustain for many of the patients.

Lipid lowering drugs

Lipid-lowering agents such as fibrates and omega-3-fatty acids can be used to lower TG levels in LPLD, however those drugs are very often not effective enough to reach treatment goals in LPLD patients. Statins should be considered to lower elevated non-HDL-Cholesterol.

Additional measures are avoidance of agents known to increase endogenous triglyceride levels, such as alcohol, estrogens, diuretics, isotretinoin, anidepressants (e.g. sertraline) and b-adrenergic blocking agents.

Gene therapy

In 2012, the European Commission approved alipogene tiparvovec (Glybera), a gene therapy for adults diagnosed with familial LPLD (confirmed by genetic testing) and suffering from severe or multiple pancreatitis attacks despite dietary fat restrictions. It was the first gene therapy to receive marketing authorization in Europe; it was priced at about $1 million per treatment, and as of 2016, only one person had been treated with it.

No specific cure has been discovered for homocystinuria; however, many people are treated using high doses of vitamin B (also known as pyridoxine). Slightly less than 50% respond to this treatment and need to take supplemental vitamin B for the rest of their lives. Those who do not respond require a Low-sulfur diet (especially monitoring methionine), and most will need treatment with trimethylglycine. A normal dose of folic acid supplement and occasionally adding cysteine to the diet can be helpful, as glutathione is synthesized from cysteine (so adding cysteine can be important to reduce oxidative stress).

Betaine (N,N,N-trimethylglycine) is used to reduce concentrations of homocysteine by promoting the conversion of homocysteine back to methionine, i.e., increasing flux through the re-methylation pathway independent of folate derivatives (which is mainly active in the liver and in the kidneys).The re-formed methionine is then gradually removed by incorporation into body protein. The methionine that is not converted into protein is converted to S-adenosyl-methionine which goes on to form homocysteine again. Betaine is, therefore, only effective if the quantity of methionine to be removed is small. Hence treatment includes both betaine and a diet low in methionine. In classical homocystinuria (CBS, or cystathione beta synthase deficiency), the plasma methionine level usually increases above the normal range of 30 micromoles/L and the concentrations should be monitored as potentially toxic levels (more than 400 micromoles/L) may be reached.

Low-protein food is recommended for this disorder, which requires food products low in particular types of amino acids (e.g., methionine).

Treatment is possible but unless continued daily, problems may arise. Currently, this is done through supplementation of 5–10 mg of oral biotin a day. If symptoms have begun to show, standard treatments can take care of them, such as hearing aids for poor hearing.

If treatment is initiated early in disease the neurologic sequelae may be reversed and further deterioration can be prevented.

Treatment normally consists of rigorous dieting, involving massive amounts of vitamin E. Vitamin E helps the body restore and produce lipoproteins, which people with abetalipoprotenimia usually lack. Vitamin E also helps keep skin and eyes healthy; studies show that many affected males will have vision problems later on in life. Developmental coordination disorder and muscle weakness are usually treated with physiotherapy or occupational therapy. Dietary restriction of triglycerides has also been useful.

In adults, fibrates and statins have been prescribed to treat hyperglycerolemia by lowering blood glycerol levels. Fibrates are a class of drugs that are known as amphipathic carboxylic acids that are often used in combination with Statins. Fibrates work by lowering blood triglyceride concentrations. When combined with statins, the combination will lower LDL cholesterol, lower blood triglycerides and increase HDL cholesterol levels.

If hyperglycerolemia is found in a young child without any family history of this condition, then it may be difficult to know whether the young child has the symptomatic or benign form of the disorder. Common treatments include: a low-fat diet, IV glucose if necessary, monitor for insulin resistance and diabetes, evaluate for Duchenne muscular dystrophy, adrenal insufficiency & developmental delay.

The Genetic and Rare Diseases Information Center (GARD) does not list any treatments at this time.

The treatment goal for individuals affected with OTC deficiency is the avoidance of hyperammonemia. This can be accomplished through a strictly controlled low-protein diet, as well as preventative treatment with nitrogen scavenging agents such as sodium benzoate. The goal is to minimize the nitrogen intake while allowing waste nitrogen to be excreted by alternate pathways. Arginine is typically supplemented as well, in an effort to improve the overall function of the urea cycle. If a hyperammonemic episode occurs, the aim of treatment is to reduce the individual's ammonia levels as soon as possible. In extreme cases, this can involve hemodialysis.

Gene therapy had been considered a possibility for curative treatment for OTC deficiency, and clinical trials were taking place at the University of Pennsylvania in the late 1990s. These were halted after the death of Jesse Gelsinger, a young man taking part in a phase I trial using an adenovirus vector. Currently, the only option for curing OTC deficiency is a liver transplant, which restores normal enzyme activity. A 2005 review of 51 patients with OTC deficiency who underwent liver transplant estimated 5-year survival rates of greater than 90%. Severe cases of OTC deficiency are typically evaluated for liver transplant by 6 months of age.

Raw eggs should be avoided in those with biotin deficiency, because egg whites contain high levels of the anti-nutrient avidin. The name avidin literally means that this protein has an "avidity" (Latin: "to eagerly long for") for biotin. Avidin binds irreversibly to biotin and this compound is then excreted in the urine.

Treatments include:

- bone marrow transplant

- ADA enzyme in PEG vehicle

LAL deficiency can be treated with sebelipase alfa is a recombinant form of LAL that was approved in 2015 in the US and EU. The disease of LAL affects < 0.2 in 10,000 people in the EU. According to an estimate by a Barclays analyst, the drug will be priced at about US $375,000 per year.

It is administered once a week via intraveneous infusion in people with rapidly progressing disease in the first six months of life. In people with less aggressive disease, it is given every other week.

Before the drug was approved, treatment of infants was mainly focused on reducing specific complications and was provided in specialized centers. Specific interventions for infants included changing from breast or normal bottle formula to a specialized low fat formula, intravenous feeding, antibiotics for infections, and steroid replacement therapy because of concerns about adrenal function.

Statins were used in people with LAL-D prior to the approval of sebelipase alfa; they helped control cholesterol but did not appear to slow liver damage; liver transplantation was necessary in most patients.

For treatment of type II, dietary modification is the initial approach, but many patients require treatment with statins (HMG-CoA reductase inhibitors) to reduce cardiovascular risk. If the triglyceride level is markedly raised, fibrates (peroxisome proliferator-activated receptor-alpha agonists) may be preferable due to their beneficial effects. Combination treatment of statins and fibrates, while highly effective, causes a markedly increased risk of myopathy and rhabdomyolysis, so is only done under close supervision. Other agents commonly added to statins are ezetimibe, niacin, and bile acid sequestrants. Dietary supplementation with fish oil is also used to reduce elevated triglycerides, with the greatest effect occurring in patients with the greatest severity. Some evidence exists for benefit of plant sterol-containing products and omega-3 fatty acids.

On September 1990, the first gene therapy to combat this disease was performed by Dr. William French Anderson on a four-year-old girl, Ashanti DeSilva, at the National Institutes of Health, Bethesda, Maryland, U.S.A.

In April 2016 the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed and recommended for approval a stem cell gene therapy called Strimvelis, for children with ADA-SCID for whom no matching bone marrow donor is available.

Some children with LAL-D have had an experimental therapy called hematopoietic stem cell transplantation (HSCT), also known as bone marrow transplant, to try to prevent the disease from getting worse. Data are sparse but there is a known high risk of serious complications including death, graft-versus-host disease.

Vitamin E supplements have shown to help children with the deficiency.

The first suspicion of SPCD in a patient with a non-specific presentation is an extremely low plasma carnitine level. When combined with an increased concentration of carnitine in urine, the suspicion of SPCD can often be confirmed by either molecular testing or functional studies assessing the uptake of carnitine in cultured fibroblasts.

Identification of patients presymptomatically via newborn screening has allowed early intervention and treatment. Treatment for SPCD involves high dose carnitine supplementation, which must be continued for life. Individuals who are identified and treated at birth have very good outcomes, including the prevention of cardiomyopathy. Mothers who are identified after a positive newborn screen but are otherwise asymptomatic are typically offered carnitine supplementation as well. The long-term outcomes for asymptomatic adults with SPCD is not known, but the discovery of mothers with undiagnosed cardiomyopathy and SPCD has raised the possibility that identification and treatment may prevent adult onset manifestations.

In terms of treatment for individuals with Nezelof syndrome, which was first characterized in 1964, includes the following(how effective bone marrow transplant is uncertain) :

- Antimicrobial therapy

- IV immunoglobulin

- Bone marrow transplantation

- Thymus transplantation

- Thymus factors

Copper deficiency is a very rare disease and is often misdiagnosed several times by physicians before concluding the deficiency of copper through differential diagnosis (copper serum test and bone marrow biopsy are usually conclusive in diagnosing copper deficiency). On average, patients are diagnosed with copper deficiency around 1.1 years after their first symptoms are reported to a physician.

Copper deficiency can be treated with either oral copper supplementation or intravenous copper. If zinc intoxication is present, discontinuation of zinc may be sufficient to restore copper levels back to normal, but this usually is a very slow process. People who suffer from zinc intoxication will usually have to take copper supplements in addition to ceasing zinc consumption. Hematological manifestations are often quickly restored back to normal. The progression of the neurological symptoms will be stopped by appropriate treatment, but often with residual neurological disability.

Treatment includes the use of iron chelating agents (such as desferrioxamine) to lower serum ferritin concentration, brain and liver iron stores, and to prevent progression of neurologic symptoms. This, combined with fresh-frozen human plasma (FFP) effectively in decreasing liver iron content. Repetitive use of FFP can even improve neurologic symptoms. Antioxidants such as vitamin E can be used simultaneously to prevent tissue damage to the liver and pancreas.

Infant mortality is high for patients diagnosed with early onset; mortality can occur within less than 2 months, while children diagnosed with late-onset syndrome seem to have higher rates of survival. Patients suffering from a complete lesion of mut0 have not only the poorest outcome of those suffering from methylaonyl-CoA mutase deficiency, but also of all individuals suffering from any form of methylmalonic acidemia.

GH treatment is not recommended for children who are not growing despite having normal levels of growth hormone, and in the UK it is not licensed for this use. Children requiring treatment usually receive daily injections of growth hormone. Most pediatric endocrinologists monitor growth and adjust dose every 3–6 months and many of these visits involve blood tests and x-rays. Treatment is usually extended as long as the child is growing, and lifelong continuation may be recommended for those most severely deficient. Nearly painless insulin syringes, pen injectors, or a needle-free delivery system reduce the discomfort. Injection sites include the biceps, thigh, buttocks, and stomach. Injection sites should be rotated daily to avoid lipoatrophy. Treatment is expensive, costing as much as US $10,000 to $40,000 a year in the USA.

According to Clinicaltrials.gov, there are no current studies on hyperglycerolemia.

Clinicaltrials.gov is a service of the U.S. National Institutes of Health. Recent research shows patients with high concentrations of blood triglycerides have an increased risk of coronary heart disease. Normally, a blood glycerol test is not ordered. The research was about a child having elevated levels of triglycerides when in fact the child had glycerol kinase deficiency. This condition is known as pseudo-hypertriglyceridemia, a falsely elevated condition of triglycerides. Another group treated patients with elevated concentrations of blood triglycerides with little or no effect on reducing the triglycerides. A few laboratories can test for high concentrations of glycerol, and some laboratories can compare a glycerol-blanked triglycerides assay with the routine non-blanked method. Both cases show how the human body may exhibit features suggestive of a medical disorder when in fact it is another medical condition causing the issue.

Treatment of VAD can be undertaken with both oral and injectable forms, generally as vitamin A palmitate.

- As an oral form, the supplementation of vitamin A is effective for lowering the risk of morbidity, especially from severe diarrhea, and reducing mortality from measles and all-cause mortality. Vitamin A supplementation of children under five who are at risk of VAD can reduce all‐cause mortality by 23%. Some countries where VAD is a public-health problem address its elimination by including vitamin A supplements available in capsule form with national immunization days (NIDs) for polio eradication or measles. Additionally, the delivery of vitamin A supplements, during integrated child health events such as child health days, have helped ensure high coverage of vitamin A supplementation in a large number of least developed countries. Child health events enable many countries in West and Central Africa to achieve over 80% coverage of vitamin A supplementation. According to UNICEF data, in 2013 worldwide, 65% of children between the ages of 6 and 59 months were fully protected with two high-dose vitamin A supplements. Vitamin A capsules cost about US$0.02. The capsules are easy to handle; they do not need to be stored in a refrigerator or vaccine carrier. When the correct dosage is given, vitamin A is safe and has no negative effect on seroconversion rates for oral polio or measles vaccines. However, because the benefit of vitamin A supplements is transient, children need them regularly every four to six months. Since NIDs provide only one dose per year, NIDs-linked vitamin A distribution must be complemented by other programs to maintain vitamin A in children Maternal high supplementation benefits both mother and breast-fed infant: high-dose vitamin A supplementation of the lactating mother in the first month postpartum can provide the breast-fed infant with an appropriate amount of vitamin A through breast milk. However, high-dose supplementation of pregnant women should be avoided because it can cause miscarriage and birth defects.

- Food fortification is also useful for improving VAD. A variety of oily and dry forms of the retinol esters, retinyl acetates, and retinyl palmitate are available for food fortification of vitamin A. Margarine and oil are the ideal food vehicles for vitamin A fortification. They protect vitamin A from oxidation during storage and prompt absorption of vitamin A. Beta-carotene and retinyl acetate or retinyl palmitate are used as a form of vitamin A for vitamin A fortification of fat-based foods. Fortification of sugar with retinyl palmitate as a form of vitamin A has been used extensively throughout Central America. Cereal flours, milk powder, and liquid milk are also used as food vehicles for vitamin A fortification. Genetic engineering is another method of food fortification, and this has been achieved with golden rice, but opposition to genetically modified foods has prevented its use as of July 2012.

- Dietary diversification can also control VAD. Nonanimal sources of vitamin A which contain preformed vitamin A account for greater than 80% of intake for most individuals in the developing world. The increase in consumption of vitamin A-rich foods of animal origin in addition to fruits and vegetables has beneficial effects on VAD. Researchers at the U. S. Agricultural Research Service have been able to identify genetic sequences in corn that are associated with higher levels of beta-carotene, the precursor to vitamin A. They found that breeders can cross certain variations of corn to produce a crop with an 18-fold increase in beta-carotene. Such advancements in nutritional plant breeding could one day aid in the illnesses related to VAD in developing countries.

Several tests can be done to discover the dysfunction of methylmalonyl-CoA mutase. Ammonia test, blood count, CT scan, MRI scan, electrolyte levels, genetic testing, methylmalonic acid blood test, and blood plasma amino acid tests all can be conducted to determine deficiency.

There is no treatment for complete lesion of the mut0 gene, though several treatments can help those with slight genetic dysfunction. Liver and kidney transplants, and a low-protein diet all help regulate the effects of the diseases.

GH deficiency is treated by replacing GH with daily injections under the skin or into muscle. Until 1985, growth hormone for treatment was obtained by extraction from human pituitary glands collected at autopsy. Since 1985, recombinant human growth hormone (rHGH) is a recombinant form of human GH produced by genetically engineered bacteria, manufactured by recombinant DNA technology. In both children and adults, costs of treatment in terms of money, effort, and the impact on day-to-day life, are substantial.