What is the treatment for vitamin D deficiency (hypovitaminosis D)?

From the Guidelines

Treatment for low vitamin D typically involves vitamin D supplementation, with the specific regimen depending on the severity of the deficiency. For most adults with vitamin D deficiency (levels below 20 ng/mL), I recommend taking vitamin D3 (cholecalciferol) at a dose of 1,000-2,000 IU daily for maintenance or 50,000 IU weekly for 8-12 weeks for more severe deficiency, followed by a maintenance dose 1. For moderate deficiency (20-30 ng/mL), a daily supplement of 800-1,000 IU is often sufficient. Take supplements with food containing some fat to improve absorption. After the initial treatment period, a follow-up blood test should be done to ensure vitamin D levels have normalized, typically aiming for levels between 30-50 ng/mL. Vitamin D is essential for calcium absorption and bone health, and deficiency can lead to bone weakening, muscle weakness, and other health issues. In addition to supplementation, try to include vitamin D-rich foods in your diet such as fatty fish, egg yolks, and fortified foods, and get moderate sun exposure when possible, as sunlight helps your body produce vitamin D naturally. Some key points to consider:

• The Institute of Medicine recommends daily dietary vitamin D intake of 600 IU in adults aged 18 to 70 years and 800 IU in adults older than 70 years 1.
• Ultraviolet B exposure may also increase vitamin D levels, but sun exposure to prevent vitamin D deficiency is not generally recommended due to the increased risk for skin cancer associated with UVB radiation 1.
• Treatment with oral vitamin D does not seem to be associated with serious harms, but toxicity can occur at very high levels (>500 nmol/L [>200 ng/mL]) 1.
• The USPSTF has published recommendations on the use of vitamin D supplementation for the prevention of falls and fractures and vitamin supplementation for the prevention of cardiovascular disease or cancer 1. It's also important to note that the evidence for screening and treatment of vitamin D deficiency is still evolving, and more research is needed to determine the optimal approach to managing this condition 1.

From the FDA Drug Label

The effectiveness of calcitriol therapy is predicated on the assumption that each patient is receiving an adequate daily intake of calcium. Patients are advised to have a dietary intake of calcium at a minimum of 600 mg daily. Caution Adequate dietary calcium is necessary for response to vitamin D therapy.

Low Vitamin D Treatment:

• The treatment for low vitamin D levels involves ensuring adequate dietary calcium intake, with a minimum of 600 mg daily.
• Calcitriol therapy is effective when the patient receives adequate daily calcium intake.
• Adequate dietary calcium is necessary for response to vitamin D therapy 2, 2, 3.

From the Research

Low Vitamin D Treatment

• The treatment of low vitamin D levels is a common practice in the United States, with about one-fifth of the adult population taking a daily supplement 4.
• The beneficial effects of vitamin D sufficiency have only recently been established, and it is still unclear how to replete low 25-hydroxyvitamin D (25[OH]D) levels, how long treatment should be continued, and how to assess and counsel patients regarding the use of vitamin D 4.
• Vitamin D supplementation can improve musculoskeletal health, reducing the rate of fractures and falls in older adults (aged ≥ 65 yrs) 5.
• The adequacy of vitamin D stores is determined by measuring the 25-hydroxyvitamin D serum concentrations, with demarcations between deficiency (< 20 ng/ml), insufficiency (20-30 ng/ml), and optimal (30-80 ng/ml) serum concentrations being controversial 5.
• Vitamin D in doses of 800-5000 IU/day can improve musculoskeletal health, and a cumulative dose of at least 600,000 IU administered over several weeks appears to be necessary to replenish vitamin D stores in patients with documented vitamin D deficiency 5.

Vitamin D Forms

• There are two forms of vitamin D: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) 6, 7.
• Vitamin D3 is considered more effective than vitamin D2 in increasing serum levels of 25(OH)D, and has a longer plasma half-life and higher affinity for the vitamin D binding protein, the hepatic vitamin D hydroxylase, and the vitamin D receptor 6, 7.
• Cholecalciferol is the only form of vitamin D that should be considered in the context of nutritional functions of fortification and supplementation, as it is the major form of vitamin D that nurtures the body and is more stable than ergocalciferol 7.
• Ergocalciferol is primarily a synthetic and less stable product, which is less potent per microgram dose than cholecalciferol, and is more susceptible to breakdown with cooking and baking 7.

Supplementation Guidelines

• Vitamin D supplementation should not be offered routinely to patient populations, except for those with documented vitamin D deficiency or at risk for developing vitamin D deficiency 5.
• The decision by young, otherwise healthy adults to take vitamin D in doses of 2000 IU/day or lower is unlikely to cause harm, and sensible sun exposure is an inexpensive and enjoyable way to maintain vitamin D stores 5.
• Single large doses of 300,000-500,000 IU should be avoided, and a cumulative dose of at least 600,000 IU administered over several weeks appears to be necessary to replenish vitamin D stores in patients with documented vitamin D deficiency 5.