Vitamin D3


Vitamin D is a fat-soluble vitamin that plays a role in bone health, several cellular processes, and maintenance of calcium and phosphorus levels in the body.

Some studies have shown that vitamin D supplementation can improve sexual functioning and increase testosterone levels in men who are vitamin D deficient.

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It is recommended that men have at least 15-50mcg (600-2,000 IU) of vitamin D per day, which can come from food, exposure to sunlight, supplements, or a combination of these. Having too much or too little can be dangerous for your health.

Vitamin D supplements can interact with certain medications. Talk to your doctor before taking vitamin D if you are already taking cholestyramine, corticosteroids, orlistat, or seizure medications.

Do not take additional vitamin D supplements in combination with Roman Testosterone Support.

What is vitamin D?

Vitamin D is a fat-soluble vitamin that is involved in several of the body’s processes. The other fat-soluble vitamins are vitamin A, vitamin E, and vitamin K, and all four of these vitamins can be stored in the fatty tissues of the body. The primary role of vitamin D in the body is to help maintain appropriate levels of calcium and phosphorus. It does this by impacting both how calcium is absorbed from food as well as how the body remodels bone, a process called bone mineralization. Vitamin D’s effects on the bone are due to its activity on cells called osteoblasts (which build bone) and osteoclasts (which reabsorb bone). Vitamin D also plays a role in certain cellular functions, like cell growth, differentiation (the process that allows a cell to do its specific job), and cell death.

Where does vitamin D come from?

Vitamin D can be obtained through food, however very few sources contain it. Animal sources include fatty fish such as salmon, beef liver, and egg yolks. Plant sources include certain kinds of mushrooms. Most food-based vitamin D in the United States comes from foods that have been fortified with vitamin D, which means it is artificially added to the food in a public health effort to help make sure everybody is getting enough each day. Foods that are often fortified with vitamin D include milk, cereal, margarine, orange juice, and yogurt (2).

Vitamin D can also be made by the body when the skin is exposed to direct sunlight. Ultraviolet B (UVB) rays from the sun cause a reaction in the skin, making vitamin D3 out of a type of cholesterol called 7-dehydrocholesterol. It is estimated that only 5-30 minutes of direct sun exposure twice weekly creates adequate levels of vitamin D in the body for most people. Factors affecting how well an individual makes vitamin D from the sun include the time of day/year, the weather, how dark the person’s skin is (how much melanin they have), and whether the person is wearing sunscreen (which blocks UVB). The latitude that somebody lives at is not a good predictor of vitamin D levels. Currently, there are no recommendations regarding how much vitamin D should be obtained from the sun, since exposure to UVB can also cause skin damage and cancer. Using sunscreen and avoiding any behaviors that might lead to sunburn are still recommended.

Before it is biologically active, vitamin D obtained from food, supplements, and sunlight needs to change form. First, the liver converts vitamin D to 25(OH)D (calcifediol). Next, the kidneys convert this compound into 1,25(OH)2D (calcitriol). Calcitriol is the active form of vitamin D in the body. Measuring 25(OH)D can be useful to assess exposure to vitamin D, however optimal levels of 25(OH)D and how exactly these levels translate to health have not been well established.

What are the health benefits of vitamin D?

Purported but unconfirmed or understudied benefits of vitamin D include preventing and treating diabetes, hypertension, and multiple sclerosis. There has also been conflicting evidence as to whether vitamin D supplementation reduces all-cause mortality. One analysis initially found that vitamin D supplementation was associated with a reduction in mortality, but a reanalysis of the data and another subsequent study did not find this association (2). More studies would need to be conducted to better elucidate whether vitamin D supplementation confers any sort of longevity benefit.

Vitamin D is essential to the proper regulation of calcium and phosphorus in the body, which is also tightly linked to bone health. As a normal part of functioning, bone is constantly being broken down and rebuilt, which requires adequate intake of both calcium and vitamin D. If either of these remains too low for too long, an individual may develop osteoporosis. As such, vitamin D supplementation is important for preventing osteoporosis, particularly in elderly men and postmenopausal women. Supplementation with both calcium and vitamin D leads to an increase in bone mineral density and a reduction in fractures in institutionalized older people, however the same result has not been seen with supplementation of vitamin D alone (2).

Studies have looked into the protective effects of vitamin D supplementation on cancer including colon, prostate, and breast cancer. While some studies have shown a protective effect, the evidence thus far is not strong enough to determine whether vitamin D supplementation is indicated (2).

Many studies have looked into the efficacy of vitamin D supplementation for the treatment of depression. One review found that, amongst the studies that did not have flaws, vitamin D supplementation is associated with improvement of depression (6).

Studies looking specifically at vitamin D’s effects on men are limited. They include the following:

Erectile dysfunction: One small study found that high levels of vitamin D were associated with high levels of both testosterone and erectile function based on a questionnaire. After supplementation with vitamin D, testosterone levels increased and erectile function improved. Doses used for supplementation were either 1,250mcg (50,000 IU) or 2,500mcg (100,000 IU) given weekly, every two weeks, every three weeks, or monthly (7).

Testosterone: One small study on vitamin D deficient, overweight men undergoing a weight reduction program found that after 1 year of supplementation with 83.3mcg (3,332 IU) per day, testosterone levels increased (5).

What to look for in a good vitamin D supplement:

As a supplement, vitamin D can come as either vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol). The biggest difference between these two forms is how they are derived: vitamin D2 comes from plant sources while vitamin D3 comes from animal sources. Within the body, both are metabolized in similar ways and many consider them to be functionally equivalent. However, some research has indicated that supplementation with vitamin D3 may be better at raising and sustaining 25(OH)D levels (3,8). There is no difference between getting vitamin D from supplements, food, or sun exposure, as each of these raises 25(OH)D levels in the body (2).

How much vitamin D is recommended?

According to the Institute of Medicine and the National Institutes of Health, the Recommended Dietary Allowance (RDA) of vitamin D is 15mcg (600 IU) per day for men and women ages 19-70. Men and women over age 70 should have 20mcg (800 IU) per day. However, the Endocrine Society states that supplementation with 37.5-50mcg (1,500-2,000 IU) per day may actually be more appropriate to maintain adequate blood levels of vitamin D (1). The RDA represents the daily amount of the vitamin that is considered sufficient to maintain bone health in healthy people. On the other end of the spectrum, the Tolerable Upper Intake Level (UL) for vitamin D is 100mcg (4,000 IU) per day for both men and women over the age of 18 (2).

How does Roman offer vitamin D?

Roman obtains vitamin D3 from non-GMO sources in China and India. It is derived from lanolin from sheep wool.

Vitamin D3 is one of five ingredients in Roman’s daily Testosterone Support supplement. The supplement consists of four tablets that should be taken with water. Each individual tablet contains 12.5mcg (500 IU) of vitamin D3, for a total daily dose of 50mcg (2,000 IU). This level fulfills both the RDA and the Endocrine Society’s recommendations for daily vitamin D intake while staying below the UL.

Other ingredients in the tablet include ashwagandha root extract, maca root powder, magnesium citrate, zinc sulfate, microcrystalline cellulose, dicalcium phosphate, stearic acid, croscarmellose sodium, magnesium stearate, silicon dioxide, and pharmaceutical glaze (shellac, Povidone).

What is vitamin D deficiency?

Exactly what qualifies as a vitamin D deficiency is not well defined. Most consider a normal 25(OH)D level to be above 50nmol/L. Below 30nmol/L is defined as a deficiency, while the range from 30-50nmol/L is considered an insufficiency (9). One study that defined vitamin D deficiency with the higher cutoff of 50nmol/L found that 39.92% of Americans are vitamin D deficient (4).

The symptoms of having low vitamin D levels include bone pain and weakness, however these are nonspecific. Severe vitamin D deficiency is classified as two different diseases: rickets and osteomalacia. Rickets is a disease that impacts children, causing skeletal deformities, bowing of the legs, and issues with bone density. Osteomalacia impacts adults, causing softer, weaker bones which may be more likely to break. Those at highest risk of developing vitamin D deficiency include breastfed infants, older adults, those with darker skin, people who spend limited time in the sunlight, people with anorexia nervosa, those with gastrointestinal issues that may impact absorption (such as inflammatory bowel disease, celiac disease, or prior gastric bypass surgery), and obese individuals.

Can you get too much vitamin D?

It is unlikely to obtain too much vitamin D from food sources or from sunlight exposure. Instances of vitamin D toxicity, which are possible at 25(OH)D levels >500nmol/L, likely result from taking high amounts of supplements. Ingesting more than the UL for vitamin D for extended periods of time can lead to adverse health effects. High levels of vitamin D lead to high levels of calcium in the blood, called hypercalcemia. This can cause calcification of the vasculature and of the tissues, leading to heart damage and kidney damage. It also increases the risk of developing kidney stones. Elevated levels of 25(OH)D have also been linked to an increase in all-cause mortality, pancreatic cancer, fractures, and falls in older adults. The symptoms of vitamin D toxicity include not eating, nausea, vomiting, abdominal pain, constipation, confusion, urinating frequently, excessive thirst, weight loss, and irregular heartbeat.

Does vitamin D interact with any other drugs?

Vitamin D supplements can interact with certain medications. If you are taking any of the following medications, it is important you talk to your doctor about your vitamin D intake (2).

  • Corticosteroids: These medications can impair how the body processes both calcium and vitamin D, contributing to osteoporosis. An example of a corticosteroid is prednisone.
  • Orlistat: This weight-loss drug decreases the amount of vitamin A, D, E, and K that your body can absorb, so you may require supplementation.
  • Cholestyramine: This cholesterol-lowering drug decreases the amount of vitamin A, D, E, and K that your body can absorb, so you may require supplementation. To counteract this interaction, cholestyramine and vitamin D should be taken at different times of the day.
  • Seizure medications: Certain seizure medications changes how your body processes vitamin D, making more of it inactive. Examples of these seizure medications include phenobarbital and phenytoin.


1. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology and Metabolism. 2011;96(7):1911-30. doi: 10.1210/jc.2011-0385.

2. Office of Dietary Supplements – Vitamin D. NIH Office of Dietary Supplements. Accessed July 22, 2019.
Oliveri B, Mastaglia SR, Brito GM, et al. Vitamin D3 seems more appropriate than D2 to sustain adequate levels of 25OHD: a pharmacokinetic approach. European Journal of Clinical Nutrition. 2015;69(6):697-702. doi:10.1038/ejcn.2015.16.

3. Oliveri B, Mastaglia SR, Brito GM, et al. Vitamin D3 seems more appropriate than D2 to sustain adequate levels of 25OHD: a pharmacokinetic approach. European Journal of Clinical Nutrition. 2015;69(6):697-702. doi:10.1038/ejcn.2015.16.

4. Parva NR, Tadepalli S, Singh P, et al. Prevalence of Vitamin D Deficiency and Associated Risk Factors in the US Population (2011-2012). Cureus. 2018. doi:10.7759/cureus.2741.

5. Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann A. Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research. 2011;43(3):223-5. doi: 10.1055/s-0030-1269854.

6. Spedding S. Vitamin D and Depression: A Systematic Review and Meta-Analysis Comparing Studies with and without Biological Flaws. Nutrients. 2014;6(4):1501-1518. doi:10.3390/nu6041501.

7. Tirabassi G, Sudano M, Salvio G, Cutini M, Muscogiuri G, Corona G, Balercia G. Vitamin D and Male Sexual Function: A Transversal and Longitudinal Study. International Journal of Endocrinology. 2018;2018(12):1-8. doi: 10.1155/2018/3720813.

8. Tripkovic L, Lambert H, Hart K, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. SciVee. 2012. doi:10.4016/48110.01.

9. UpToDate. Accessed July 22, 2019.