Alternatively, a single-dose therapy is used for instance if there are concerns regarding the patient's compliance. The single-dose therapy can be given as an injection, but is normally given in form of an oral medication.

For treating rickets, the American Academy of Pediatrics (AAP) has recommended that pediatric patients receive an initial two- to three-month treatment of "high-dose" vitamin D therapy. In this regime, the daily dose of cholecalciferol is 1,000 IU for newborns, 1,000 to 5,000 IU for 1- to 12-months old infants, and 5,000 IU for patients over 1 year of age.

For adults, other dosages have been called for. A review of 2008/2009 recommended dosages of 1,000 IU cholecalciferol per 10 ng/ml required serum increase, to be given daily over two to three months. In another proposed cholecalciferol loading dose guideline for vitamin D-deficient adults, a weekly dosage is given, up to a total amount that is proportional to the required serum increase (up to the level of 75 nml/l) and, within certain body weight limits, to body weight.

These treatments have been used to help treat or manage toxicity in animals. Although not considered part of standard treatment, they might be of some benefit to humans.

- Vitamin E appears to be an effective treatment in rabbits, prevents side effects in chicks

- Taurine significantly reduces toxic effects in rats. Retinoids can be conjugated by taurine and other substances. Significant amounts of retinotaurine are excreted in the bile, and this retinol conjugate is thought to be an excretory form, as it has little biological activity.

- Cholestin - significantly reduces toxic effects in rats.

- Vitamin K prevents hypoprothrombinemia in rats and can sometimes control the increase in plasma/cell ratios of vitamin A.

If liver damage has progressed into fibrosis, synthesizing capacity is compromised and supplementation can replenish PC. However, recovery is dependent on removing the causative agent; stopping high Vitamin A intake.

Day to day requirements of vitamin d are set around 800-1000IU to maintain healthy levels which in most cases can be provided by sun exposure. Increased amounts are required for individuals who are previously diagnosed as deficient. For those of moderate deficiencies,oral supplementation can be implemented into the diet at levels of 3000-5000 IU per day for a 6- to 12-week period continued by an ongoing reduced dose of 1000- 2000 IU per day to maintain stores in the body.

Severe deficiency is treated through megadose therapy where patients are given doses around 100 000 IU to assist in raising stores faster to ensure physical health in restored to prevent further illness or disease.

With few exceptions, like some vitamins from B-complex, hypervitaminosis usually occurs more with fat-soluble vitamins (D, E, K and A or 'DEKA'), which are stored in the liver and fatty tissues of the body. These vitamins build up and remain for a longer time in the body than water-soluble vitamins.

Conditions include:

- Hypervitaminosis A

- Hypervitaminosis D

- Hypervitaminosis E

- Hypervitaminosis K, unique as the true upper limit is less clear as is its bioavailability.

According to Williams' Essentials of Diet and Nutrition Therapy it is difficult to set a DRI for vitamin K because part of the requirement can be met by intestinal bacterial synthesis.

- Reliable information is lacking as to the vitamin K content of many foods or its bioavailability. With this in mind the Expert Committee established an AI rather than an RDA.

- This RDA (AI for men age 19 and older is 120 µg/day, AI for women is 90 µg/day) is adequate to preserve blood clotting, but the correct intake needed for optimum bone health is unknown. Toxicity has not been reported.

High-dosage A; high-dosage, slow-release vitamin B; and very high-dosage vitamin B alone (i.e. without vitamin B complex) hypervitaminoses are sometimes associated with side effects that usually rapidly cease with supplement reduction or cessation.

High doses of mineral supplements can also lead to side effects and toxicity. Mineral-supplement poisoning does occur occasionally, most often due to excessive intake of iron-containing supplements.

Treatment involves increasing dietary intake of calcium, phosphates and vitamin D. Exposure to ultraviolet B light (most easily obtained when the sun is highest in the sky), cod liver oil, halibut-liver oil, and viosterol are all sources of vitamin D.

A sufficient amount of ultraviolet B light in sunlight each day and adequate supplies of calcium and phosphorus in the diet can prevent rickets. Darker-skinned people need to be exposed longer to the ultraviolet rays. The replacement of vitamin D has been proven to correct rickets using these methods of ultraviolet light therapy and medicine.

Recommendations are for 400 international units (IU) of vitamin D a day for infants and children. Children who do not get adequate amounts of vitamin D are at increased risk of rickets. Vitamin D is essential for allowing the body to uptake calcium for use in proper bone calcification and maintenance.

Nutritional osteomalacia responds well to administration of 2,000-10,000 IU of vitamin D3 by mouth daily. Vitamin D3 (cholecalciferol) is typically absorbed more readily than vitmin D2 (ergocalciferol). Osteomalacia due to malabsorption may require treatment by injection or daily oral dosing of significant amounts of vitamin D3.

Pregnancy also poses as another high risk factor for vitamin D deficiency. The status levels of vitamin D during the last stages of pregnancy directly impact the new borns first initial months of life. Babies who are exclusively breastfed with minimal exposure to sunlight or supplementation can be at greater risk of vitamin D deficiency,as human milk has minimal vitamin D present. Recommendations for infants of the age 0–12 months are set at 5 ug/day, to assist in preventing rickets in young babies. 80% of dark skinned and or veiled women in Melbourne were found to have serum levels lower than 22.5 nmol/L considering them to be within moderate ranges of vitamin D deficiency.

Sufficient vitamin D levels can also be achieved through dietary supplementation and/or exposure to sunlight. Vitamin D (cholecalciferol) is the preferred form since it is more readily absorbed than vitamin D. Most dermatologists recommend vitamin D supplementation as an alternative to unprotected ultraviolet exposure due to the increased risk of skin cancer associated with sun exposure. Endogenous production with full body exposure to sunlight is approximately 250 µg (10,000 IU) per day.

According to the American Academy of Pediatrics (AAP), all infants, including those who are exclusively breast-fed, may need vitamin D supplementation until they start drinking at least of vitamin D-fortified milk or formula a day.

At this time there is no treatment for transaldolase deficiency.

There is currently research being done to find treatments for transaldolase deficiency. A study done in 2009 used orally administered N-acetylcysteine on transaldolase deficient mice and it prevented the symptoms associated with the disease. N-acetylcysteine is a precursor for reduced glutathione, which is decreased in transaldolase deficient patients.

An excess of vitamin D causes abnormally high blood concentrations of calcium, which can cause overcalcification of the bones, soft tissues, heart and kidneys. In addition, hypertension can result.Symptoms of vitamin D toxicity may include the following:

- Dehydration

- Vomiting

- Decreased appetite

- Irritability

- Constipation

- Fatigue

- Muscle weakness

- Metastatic calcification of the soft tissues

Hypervitaminosis D symptoms appear several months after excessive doses of vitamin D are administered. In almost every case, a low-calcium diet combined with corticosteroid drugs will allow for a full recovery within a month. There is a theory that some of the symptoms of vitamin D toxicity are actually due to vitamin K depletion. One animal experiment has demonstrated that co-consumption with vitamin K reduced adverse effects, but this has not been tested in humans.

Hypervitaminosis D is a state of vitamin D toxicity. The normal range for blood concentration is 30.0 to 74.0 nanograms per milliliter (ng/mL).

Prevention of osteomalacia rests on having an adequate intake of vitamin D and calcium. Vitamin D3 Supplementation is often needed due to the scarcity of Vitamin D sources in the modern diet.

Supplemental zinc can prevent iron absorption, leading to iron deficiency and possible peripheral neuropathy, with loss of sensation in extremities. Zinc and iron should be taken at different times of the day.

Hypervitaminosis is a condition of abnormally high storage levels of vitamins, which can lead to toxic symptoms. Specific medical names of the different conditions are derived from the vitamin involved: an excess of vitamin A, for example, is called hypervitaminosis A.

Hypervitaminoses are primarily caused by fat-soluble vitamins (D, E, K and A), as these are stored by the body for longer period than the water-soluble vitamins.

Generally, toxic levels of vitamins stem from high supplement intake and not from natural food. Toxicities of fat-soluble vitamins can also be caused by a large intake of highly fortified foods, but natural food rarely deliver dangerous levels of fat-soluble vitamins. The Dietary Reference Intake recommendations from the United States Department of Agriculture define a "tolerable upper intake level" for most vitamins.

Zinc has been used therapeutically at a dose of 150 mg/day for months and in some cases for years, and in one case at a dose of up to 2000 mg/day zinc for months. A decrease in copper levels and hematological changes have been reported; however, those changes were completely reversed with the cessation of zinc intake.

However, zinc has been used as zinc gluconate and zinc acetate lozenges for treating the common cold and therefore the safety of usage at about 100 mg/day level is a relevant question. Thus, given that doses of over 150 mg/day for months to years has caused no permanent harm in many cases, a one-week usage of about 100 mg/day of zinc in the form of lozenges would not be expected to cause serious or irreversible adverse health issues in most persons.

Unlike iron, the elimination of zinc is concentration-dependent.

Hypervitaminosis E is a state of vitamin E toxicity. Since vitamin E can act as an anticoagulant and may increase the risk of bleeding problems, many agencies have set a tolerable upper intake levels (UL) for vitamin E at 1,000 mg (1,500 IU) per day. This UL was established due to an increased incidence of hemorrhaging with higher doses of supplemental vitamin E. Doses of vitamin E above the UL can also magnify the antiplatelet effects of certain drugs such as anti-coagulant medications and aspirin, which can cause life-threatening symptoms in ill patients. Hypervitaminosis E may also counteract vitamin K, leading to a vitamin K deficiency.

There is no treatment for MKD. But, the inflammation and the other effects can be reduced to a certain extent.

- IL-1 targeting drugs can be used to reduce the effects of the disorder. Anakinra is antagonist to IL-1 receptors. Anakinra binds the IL-1 receptor, preventing the actions of both IL-1α and IL-1β, and it has been proved to reduce the clinical and biochemical inflammation in MKD. It can effectively decreases the frequency as well as the severity of inflammatory attacks when used on a daily basis. Disadvantages with the usage of this drug are occurrence of painful injection site reaction and as the drug is discontinued in the near future the febrile attacks start. (Examined in a 12-year-old patient).

- Canakinumab is a long acting monoclonal antibody which is directed against IL-1β has shown to be effective in reducing both frequency and severity in patients suffering from mild and severe MKD in case reports and observational case series. It reduces the physiological effects but the biochemical parameter still remain elevated (Galeotti et al. demonstrated that it is more effective than anakinra –considered 6 patients suffering from MKD).

- Anti-TNF therapy might be effective in MKD, but the effect is mostly partial and therapy failure and clinical deterioration have been described frequently in patients on infliximab or etanercept. A beneficial effect of human monoclonal anti-TNFα antibody adalimumab was seen in a small number of MKD patients.

- Most MKD patients are benefited by anti-IL-1 therapy. However, anti-IL-1-resistant disease may also occur. Example. tocilizumab (a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor). This drug is used when the patients are unresponsive towards Anakinra. (Shendi et al. treated a young woman in whom anakinra was ineffective with tocilizumab). It was found that it was effective in reducing the biochemical and clinical inflammation [30].Stoffels et al. observed reduction of frequency and severity of the inflammatory attacks, although after several months of treatment one of these two patients persistently showed mild inflammatory symptoms in the absence of biochemical inflammatory markers.

- A beneficial effect of hematopoietic stem cell transplantation can be used in severe mevalonate kinase deficiency conditions (Improvement of cerebral myelinisation on MRI after allogenic stem cell transplantation was observed in one girl). But, liver transplantation did not influence febrile attacks in this patient.

Management of this condition includes|:

- Intravenous calcium gluconate 10% can be administered, or if the hypocalcaemia is severe, calcium chloride is given instead. This is only appropriate if the hypocalcemia is acute and has occurred over a relatively short time frame. But if the hypocalcemia has been severe and chronic, then this regimen can be fatal, because there is a degree of acclimatization that occurs. The neuromuscular excitability, cardiac electrical instability, and associated symptoms are then not cured or relieved by prompt administration of corrective doses of calcium, but rather exacerbated. Such rapid administration of calcium would result in effective over correction – symptoms of hypercalcemia would follow.

- However, in either circumstance, maintenance doses of both calcium and vitamin-D (often as 1,25-(OH)-D, i.e. calcitriol) are often necessary to prevent further decline

A vitamin deficiency can cause a disease or syndrome known as an avitaminosis or hypovitaminosis. This usually refers to a long-term deficiency of a vitamin. When caused by inadequate nutrition it can be classed as a "primary deficiency", and when due to an underlying disorder such as malabsorption it can be classed as a "secondary deficiency". An underlying disorder may be metabolic as in a defect converting tryptophan to niacin. It can also be the result of lifestyle choices including smoking and alcohol consumption.

Examples are vitamin A deficiency, folate deficiency, scurvy, vitamin D deficiency, vitamin E deficiency, and vitamin K deficiency. In the medical literature, any of these may also be called by names on the pattern of "hypovitaminosis" or "avitaminosis" + "[letter of vitamin]", for example, hypovitaminosis A, hypovitaminosis C, hypovitaminosis D.

Conversely hypervitaminosis is the syndrome of symptoms caused by over-retention of fat-soluble vitamins in the body.

- Vitamin A deficiency can cause keratomalacia.

- Thiamine (vitamin B1) deficiency causes beriberi and Wernicke–Korsakoff syndrome.

- Riboflavin (vitamin B2) deficiency causes ariboflavinosis.

- Niacin (vitamin B3) deficiency causes pellagra.

- Pantothenic acid (vitamin B5) deficiency causes chronic paresthesia.

- Vitamin B6

- Biotin (vitamin B7) deficiency negatively affects fertility and hair/skin growth. Deficiency can be caused by poor diet or genetic factors (such as mutations in the BTD gene, see multiple carboxylase deficiency).

- Folate (vitamin B9) deficiency is associated with numerous health problems. Fortification of certain foods with folate has drastically reduced the incidence of neural tube defects in countries where such fortification takes place. Deficiency can result from poor diet or genetic factors (such as mutations in the MTHFR gene that lead to compromised folate metabolism).

- Vitamin B12 (cobalamin) deficiency can lead to pernicious anemia, megaloblastic anemia, subacute combined degeneration of spinal cord, and methylmalonic acidemia among other conditions.

- Vitamin C (ascorbic acid) short-term deficiency can lead to weakness, weight loss and general aches and pains. Longer-term depletion may affect the connective tissue. Persistent vitamin C deficiency leads to scurvy.

- Vitamin D (cholecalciferol) deficiency is a known cause of rickets, and has been linked to numerous health problems.

- Vitamin E deficiency causes nerve problems due to poor conduction of electrical impulses along nerves due to changes in nerve membrane structure and function.

- Vitamin K (phylloquinone or menaquinone) deficiency causes impaired coagulation and has also been implicated in osteoporosis

Resection of the tumor is the ideal treatment and results in correction of hypophosphatemia (and low calcitriol levels) within hours of resection. Resolution of skeletal abnormalities may take many months.

If the tumor cannot be located, treatment with calcitriol (1-3 µg/day) and phosphorus (1-4 g/day in divided doses) is instituted. Tumors which secrete somatostatin receptors may respond to treatment with octreotide. If hypophosphatemia persists despite calcitriol and phosphate supplementation, administration of cinacalcet has been shown to be useful

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.

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.

One drug that has been tried is Miglustat. Miglustat is a glucosylceramide synthase inhibitor, which inhibits the synthesis of glycosphingolipids in cells. It has been shown to delay the onset of disease in the NPC mouse, and published data from a multi-center clinical trial of Miglustat in the United States and England and from case reports suggests that it may ameliorate the course of human NPC.

Several other treatment strategies are under investigation in cell culture and animal models of NPC. These include, cholesterol mobilization, neurosteroid (a special type of hormone that affects brain and other nerve cells) replacement using allopregnanolone, rab overexpression to bypass the trafficking block (Pagano lab) and Curcumin as an anti-inflammatory and calcium modulatory agent. The pregnane X receptor has been identified as a potential target.

Neural stem cells have also been investigated in an animal model, and clear evidence of life extension in the mouse model has been shown.

Low cholesterol diets are often used, but there is no evidence of efficacy.