Vitamin D supplement guideline

Vitamin D, actually it's a hormone

Vitamin D ( Calcitriol ) is a fat-soluble vitamin that has hormone liked structure or so-called prohormone, in which kidneys produce vitamin D to controls blood calcium concentration and impact the immune system.

The function of vitamin D

  • Maintaining healthy bones prevent Osteopenia and Osteoporosis

  • Anti-inflammatory

  • Antioxidant

  • Neuroprotective properties

  • Support immune health

  • Support muscle function

  • Support brain cell activity

Research on vitamin D use for specific conditions shows:

  • Vitamin D for cancer prevention, vitamin D supplementation may reduce the risk of certain cancers. Numerous epidemiologic studies have shown that higher intake or blood levels of vitamin D are associated with a reduced risk of colorectal cancer , breast cancer, and prostate cancer More detail

  • Cognitive health. Research shows that low levels of vitamin D in the blood are associated with cognitive decline. However, more studies are needed to determine the benefits of vitamin D supplementation for cognitive health. The researchers believe that because vitamin D is important to healthy brain function, insufficient nutrient levels may play a role in depression and other mental illnesses. An earlier 2005 study identified vitamin D receptors in the same areas of the brain associated with depression.

  • Depression Studies have shown a link between vitamin D deficiency and depression. Researchers behind a 2013 meta-analysis noticed that study participant with depression also had low vitamin D levels. The same analysis found that, statistically, people with low vitamin D were at a much greater risk of depression. more details

  • Osteoporosis. Studies suggest that people who get enough vitamin D and calcium in their diets can slow bone mineral loss, help prevent osteoporosis and reduce bone fractures. Ask your doctor if you need a calcium and vitamin D supplement to prevent or treat osteoporosis.

  • Diabetes and insulin insufficiency There is mechanistic support that vitamin D may influence both insulin secretion and insulin sensitivity and subsequently T2DM incidence. Cross-sectional and prospective studies support the role of vitamin D in the prevention of T2DM.

  • Vitamin D and immune system Vitamin D has been used to treat infections such as tuberculosis before the advent of effective antibiotics. Where treatment included exposure to sunlight, Cod liver oil, a rich source of vitamin D has also been employed as a treatment for tuberculosis as well as for generally increased protection from infections. There have been multiple cross-sectional studies associating lower levels of vitamin D with increased infection. One report studied almost 19,000 subjects between found that individuals with lower vitamin D levels (<30 ng/ml) were more likely to self-report a recent upper respiratory tract infection than those with sufficient levels. Vitamin D can modulate immune responses. Deficiency in vitamin D is associated with increased autoimmunity as well as increased susceptibility to infection. Read original research

Source of vitamin D

Vitamin D isn't naturally found in many foods. It's naturally present in fatty fish such as salmon, mackerel, and sardines or fortified food such as milk or serial. Vitamin D is also produced endogenously when ultraviolet (UVB) rays from sunlight strike the skin and trigger vitamin D synthesis.

Checking your vitamin D level

Blood check for 25-Hydroxyvitamin D2 and D3, Serum

  • <10 ng/mL (severe deficiency)Could be associated with osteomalacia or rickets

  • 10-19 ng/mL (mild to moderate deficiency)May be associated with increased risk of osteoporosis or secondary

  • 20-50 ng/mL (optimum levels) Sustained levels >50 ng/mL 25OH-VitD along with prolonged calcium supplementation may lead to hypercalciuria and decreased renal function

  • 51-80 ng/mL (increased risk of hypercalciuria)

  • >80 ng/mL (toxicity possible)

For more detail about lab check for vitamin D levels click

Treatment for vitamin D deficiency

The regimen is oral ergocalciferol weekly for eight weeks. The goal is to achieve a minimum level of 30 ng per mL.

Serum 25-hydroxyvitamin D levels should be measured again after completion of therapy, and if values have not reached or exceeded the minimum level, a second eight-week course of ergocalciferol should be prescribed.

If the serum 25-hydroxyvitamin D levels still have not risen, the most likely cause is nonadherence to therapy or malabsorption. If malabsorption is suspected, consultation with a gastroenterologist should be considered.

After vitamin D levels are replete, maintenance dosages of cholecalciferol should be instituted at 800 to 1,000 IU per day from dietary and supplemental sources

For more detail about treatment click

Common Q and A

What's the difference between vitamin D2 and D3

Vitamin D forms and production

Two major forms of vitamin D that are important to humans are vitamin

  • D2 (ergocalciferol) is made naturally by plants

  • D3 (cholecalciferol) is made naturally by the body when the skin is exposed to ultraviolet radiation in sunlight.

Both forms are converted to 25-hydroxyvitamin D in the liver. 25-Hydroxyvitamin D then travels through the blood to the kidneys, where it is further modified to 1,25-dihydroxyvitamin D, or calcitriol, the active form of vitamin D in the body. The most accurate method of evaluating a person’s vitamin D status is to measure the level of 25-hydroxyvitamin D in the blood.

Is there any harm from having too much vitamin D in the body?

Excessive intake of vitamin D can cause toxic effects. Too much vitamin D can be harmful because it increases calcium levels, which can lead to a deposit of calcium salts in soft tissues, such as the kidneys, heart, or lungs, and hypercalcemia (high blood levels of calcium). Vitamin D toxicity clinical can be

  • Confusion and disorientation

  • Heart rhythm problems

  • Kidney stones and kidney damage

  • Nausea and vomiting

  • Poor appetite and weight loss

  • Constipation

  • Weakness

80 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal renal function. Most patients with toxicity have levels >150 ng/mL. Patients with renal failure can have very high 25-OH-VitD levels without any signs of toxicity, as renal conversion to the active hormone 1,25-OH-VitD is impaired or absent.

Low level of vitamin D and cancer risk research, how does it start?

Early epidemiologic research showed that the death rates for certain cancers were lower among individuals living in southern latitudes, where levels of sunlight exposure are relatively high than among those living at northern latitudes. Because exposure to ultraviolet light from sunlight leads to the production of vitamin D, researchers hypothesized that variation in vitamin D levels might account for this association.

Experimental evidence has also suggested a possible association between vitamin D and cancer risk. In studies of cancer cells and of tumors in mice, vitamin D has been found to have several activities that might slow or prevent the development of cancer, including promoting cellular differentiation, decreasing cancer cell growth, stimulating cell death (apoptosis), and reducing tumor blood vessel formation (angiogenesis).

I currently use other kinds of supplement and medication would it has interaction with vitamin D supplement?

Vitamin can cause drug interaction with some drugs such as heart medication, cytochrome P450 metabolism medication. You can click to check drugs that have a drug interaction with vitamin D.

Risk factors for vitamin D deficiency

  • Limited sun exposure, sedentary lifestyle

  • Fatty and animal fat are rich sources of vitamin D.If you adhere to a vegan or vegetarian diet, there’s a chance you’re not getting enough vitamin D.

  • Darker skin tone; People who have darker skin have greater amounts of melanin, a natural pigment that gives skin its color. Melanin reduces vitamin D production in the skin.

  • Living in higher altitude: If the area where you live gets less sun, you may need to spend more time outside to increase your sun exposure.

  • Obesity: People who are obese may need to absorb more vitamin D than people of average weight in order to reach recommended nutrient levels.

  • Elderly; As you get older, your skin becomes less efficient at synthesizing vitamin D.

  • People with kidney and liver disease.

  • Medication use that alters vitamin D metabolism (e.g., anticonvulsants, glucocorticoids)

  • Sunscreen wearing; studies estimate that sunscreen of SPF 30 or more reduces vitamin D production in the body by about 95–98%.

How to get adequate vitamin D from sunlight?

Wearing a tank top and shorts for 10–30 minutes three times per week during the summer should be sufficient for most people with lighter skin.

Contraindications to Vitamin D Supplementation

  • Granulomatous diseases (e.g., tuberculosis)

  • Metastatic bone disease

  • Sarcoidosis

  • Williams syndrome


  1. " Vitamin D "

  2. Cynthia Aranow, MD, J Investig Med in PMC 2012 Aug 1. "Vitamin D and the Immune System"

  3. Annamarya Scaccia, 6 august 2020,'Is a Vitamin D Deficiency Causing Your Depression?'

  4. Test ID: 25HDN 25-Hydroxyvitamin D2 and D3, Serum

  5. PAULA BORDELON, DO; MARIA V. GHETU, MD; and ROBERT LANGAN, MD, St. Luke's Family Medicine Residency Program, Bethlehem, Pennsylvania"Recognition and Management of Vitamin D Deficiency"

18 views0 comments

Recent Posts

See All