Vitamin D deficiency in men: causes, the research, and what to eat
The studies and sources we used are listed at the end. Editorial policy
Vitamin D is known as a bone nutrient, but its links with testosterone and erections have been studied too. Most men get far less from food than recommended. Here is why, and what to eat and how much.
The US recommended amount (RDA) of vitamin D for men is 15 µg (600 IU) a day, and 20 µg (800 IU) over 70. US men get about 5.1 µg (204 IU) a day from food and drink, a third of that. Most vitamin D is made in the skin in sunlight, and indoor life cuts that down: in a Tokyo study of 5,518 health-check patients, about 98% were below 30 ng/mL. Observational studies report more severe ED in men low in vitamin D, but trials disagree on whether supplements raise testosterone. Start with oily fish such as salmon and trout, fortified foods and a little sun.
Contents
- What vitamin D does
- How much men need, and how much they get
- How many men are actually low?
- Why men today run low
- How much sun is enough?
- Research on testosterone and ED
- Foods high in vitamin D
- If you take a supplement, mind the upper limit
- If you want to check your everyday meals
- When to see a doctor
- FAQ
- References
- Keep reading
What vitamin D does
Vitamin D helps the gut absorb calcium and phosphorus and keeps blood calcium steady. It is needed for bones and teeth, and plays a part in how nerves and muscles work.
Unlike other vitamins, it does not only come from food: the skin makes it in sunlight (UVB). A long-term shortfall can soften the bones in adults (osteomalacia) and, with age, add to the risk of osteoporosis and fractures.
How much men need, and how much they get
| Men | A day |
|---|---|
| US RDA, 19–70 | 15 µg (600 IU) |
| US RDA, over 70 | 20 µg (800 IU) |
| Upper limit, adults | 100 µg (4,000 IU) |
| Average US man, from food and drink | 5.1 µg (204 IU) |
NIH Office of Dietary Supplements; average intake from the US national survey (NHANES 2015–2016). 1 µg = 40 IU.
Very few foods are rich in vitamin D apart from oily fish, so for most men food alone falls well short of the RDA. That is why sunlight, and for many people fortified foods or supplements, make up the rest.
How many men are actually low?
Intake is only part of the story; blood levels of 25(OH)D show the whole picture, sun included. In US survey data from 2011–2014, 5% of people aged 1 and over were below 30 nmol/L (12 ng/mL), the level linked with deficiency, and another 18% were between 30 and 49 nmol/L (12 to 19.6 ng/mL), generally considered inadequate.
- Method
- Measured blood 25(OH)D, the usual marker of vitamin D status, with a newer, more precise method
- Found
- About 98% were below 30 ng/mL, the cut-off used by the Japan Endocrine Society. The authors point to less time outdoors and less traditional food
- Caveat
- City health-check patients only. Cut-offs differ: the US Food and Nutrition Board considers 20 ng/mL (50 nmol/L) or more adequate for most people, so far fewer would count as low by that measure
Why men today run low
- Time indoors: the UVB that makes vitamin D does not pass through glass, so sun through an office or car window makes none. If you are indoors most of the day apart from your commute, you get very little.
- Sunscreen: sunscreen with SPF 8 or more appears to block vitamin D-making UV, though in practice most people apply too little to block it completely.
- Season and latitude: the season, time of day, length of day and cloud all change how much UV reaches you. Winter sun is weaker, and the further from the equator you live, the bigger the winter drop.
- Little oily fish: oily fish is the main natural food source. If you eat it once a week or less, meat, grains and vegetables add almost nothing.
How much sun is enough?
Japan's National Institute for Environmental Studies estimated how long the face and backs of both hands (about 600 cm²) need in clear midday sun to make 5.5 µg of vitamin D:
| Place and month | Time needed at noon |
|---|---|
| Tsukuba (36°N), July | about 3.5 minutes |
| Tsukuba (36°N), December | about 22 minutes |
| Sapporo (43°N), December | about 76 minutes |
Miyauchi et al., 2013. Assumes no vitamin D from food. In Tsukuba in December it took about 106 minutes at 9 am and about 271 minutes at 3 pm.
These are Japanese cities, but latitude is what matters: London is at about 51°N, further north than Sapporo, and so are northern US states such as Washington and Minnesota. In summer a few minutes is enough; in winter a short lunchtime walk may not be, so food matters more. Keep summer sun short to avoid burning.
Research on testosterone and ED
Vitamin D has been studied for links with testosterone and erections, but what is known is still limited.
- Found
- Average vitamin D did not differ much between men with and without ED. But men low in vitamin D had lower erectile function scores, and the more severe the ED, the lower the vitamin D tended to be, also among men with normal testosterone
- Caveat
- All observational, so it cannot show that low vitamin D causes ED. Another analysis of 7 studies and 4,132 men (Wei et al., 2019) found no strong link
On testosterone, supplement trials disagree:
- A rise: in 54 men low in vitamin D, taking part in a German weight-loss trial (Pilz et al., 2011), those who took 83 µg (3,332 IU) a day for a year had a small rise in total testosterone. A small study, run as part of a weight-loss trial.
- No difference: in 100 healthy men with lowish testosterone (Lerchbaum et al., 2019), 500 µg (20,000 IU) a week for 12 weeks made no difference to testosterone.
- Pooled trials: a 2019 analysis of 8 trials found no clear difference in total testosterone.
Bringing a low level back to normal makes sense, but it cannot be said that taking vitamin D raises testosterone. For the wider picture, see how to raise testosterone naturally.
Foods high in vitamin D
The main natural sources are oily fish and eggs; meat, grains and vegetables have almost none. Amounts are from the NIH Office of Dietary Supplements.
Salmon
Vitamin D
3 oz (85 g) sockeye, cooked: about 14.2 µg (570 IU)
Close to the full RDA in one portion. Farmed trout: about 16.2 µg per 3 oz
Photo: 
Eggs
Vitamin D
1 large egg: about 1.1 µg (44 IU)
Fortified foods help many people make up the rest: a cup of fortified milk has about 2.9 µg (120 IU), fortified soy, almond or oat milk 2.5 to 3.6 µg, and a serving of fortified cereal about 2.0 µg. White mushrooms exposed to UV light have about 9.2 µg per half cup; check the label, as ordinary mushrooms have far less. Fortification differs by country and brand, so read the label.
For other nutrients men tend to miss, see nutrients men lack, by country.
If you take a supplement, mind the upper limit
If you rarely eat oily fish, or spend little time outdoors in winter, a supplement is one option. Labels may use IU: 1 µg is 40 IU. Doses per tablet vary a lot, so read the label.
The thing to watch is taking too much. The upper limit for adults is 100 µg (4,000 IU) a day. Too much can raise blood calcium (hypercalcemia), causing nausea, loss of appetite, weakness, thirst, passing a lot of urine and kidney stones. Stacking products can push you over without noticing.
- Check you are not taking a multivitamin and a separate vitamin D at the same time.
- If you have kidney disease or take medicines, ask your doctor or pharmacist first.
If you want to check your everyday meals
Vitamin D swings widely between days with and without fish, so one day tells you little. Looking back over one or two weeks of meals shows how often fish actually appears.
Estimates from a photo are rough guides, not exact amounts, and say nothing about effects on your body.
When to see a doctor
Do not just increase a supplement on your own; see a doctor if:
- bone or back pain keeps going, or you broke a bone in a minor fall: your doctor can check for osteoporosis.
- you take a supplement and have ongoing nausea, poor appetite, thirst or pass a lot of urine: you may be taking too much. Stop it and see your doctor.
- erections suddenly became harder, or low sex drive and low energy keep going: see a urologist or your doctor. ED can be a sign of diabetes, high blood pressure or heart disease, and testosterone can be tested.
- you have blood in your urine, pain when urinating or a fever: this points to something other than nutrition; see a doctor soon.
FAQ
Is it harder to get enough vitamin D in winter?
Yes. Weaker winter sun means the skin makes less. A Japanese estimate found that making a set amount of vitamin D on the face and backs of the hands at noon took about 3.5 minutes in July but about 22 minutes in December in Tsukuba (36°N), and about 76 minutes in December in Sapporo (43°N). Most of the UK lies further north still, so in winter food such as oily fish matters more.
Do vitamin D supplements raise testosterone?
The trials disagree. In 54 men low in vitamin D who took it for a year, total testosterone rose slightly. In a 12-week trial of 100 men with lowish testosterone, and in an analysis of 8 trials, there was no clear difference. It cannot be said that vitamin D raises testosterone.
Does sunscreen stop my skin making vitamin D?
According to the NIH Office of Dietary Supplements, sunscreen with SPF 8 or more appears to block the UV rays that make vitamin D, although in practice most people apply too little to block it completely. Too much sun harms the skin, so a sensible approach is a few minutes on the face and hands, with the rest from food.
How can I find out whether I am low?
A blood test for 25-hydroxyvitamin D, or 25(OH)D, shows your vitamin D status. Ask your doctor whether it is worth testing. If you have bone pain or have broken a bone after a minor fall, raise that too.
References
- NIH Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
- Miyamoto H, et al. Determination of a Serum 25-Hydroxyvitamin D Reference Ranges in Japanese Adults Using Fully Automated Liquid Chromatography-Tandem Mass Spectrometry. J Nutr. 2023;153(4):1253-1264. pesquisa.bvsalud.org/sms/resource/pt/mdl-36806449
- National Institute for Environmental Studies (Japan). Estimated sun exposure time needed to make the vitamin D the body needs (Miyauchi M, et al. J Nutr Sci Vitaminol. 2013;59:257-263). In Japanese. cger.nies.go.jp/ja/about/results/2013/13030.html
- Crafa A, et al. Is There an Association Between Vitamin D Deficiency and Erectile Dysfunction? A Systematic Review and Meta-Analysis. Nutrients. 2020;12(5):1411. pmc.ncbi.nlm.nih.gov/articles/PMC7284343/
- Wei Y, Chen P, Chen Q, Zhu H. Serum vitamin D levels and erectile dysfunction: A systematic review and meta-analysis. Andrologia. 2019;51(3):e13211. pubmed.ncbi.nlm.nih.gov/30523636/
- Pilz S, et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011;43(3):223-225 (summary by CATIE). catie.ca/treatmentupdate-185/can-vitamin-d-increase-testoste
- Lerchbaum E, et al. Effects of vitamin D supplementation on androgens in men with low testosterone levels: a randomized controlled trial. Eur J Nutr. 2019. pubmed.ncbi.nlm.nih.gov/30460609/
- The effect of vitamin D supplementation on the androgenic profile in men: a systematic review and meta-analysis of clinical trials. Andrologia. 2019;51(9):e13343. pesquisa.bvsalud.org/ses/resource/pt/mdl-31332821
