Vitamin D for Men: How Much D3 and K2 You Need and When to Take It

Men need 600 IU (15 mcg) of vitamin D a day up to age 70 and 800 IU (20 mcg) after that, with an upper limit of 4,000 IU (100 mcg) a day from all sources. Men average only about 204 IU (5.1 mcg) a day from food, so sunlight or a supplement usually fills the gap, especially in winter. Pairing vitamin D3 with vitamin K2 makes sense for men too: vitamin D helps you absorb calcium, and K2 activates osteocalcin, the protein that binds calcium into bone.

Key Takeaways

• Men need 600 IU (15 mcg) of vitamin D a day from 19 to 70 and 800 IU (20 mcg) after 70; the upper limit is 4,000 IU (100 mcg) a day (NIH ODS: Vitamin D).
• Men's average intake from food is about 204 IU (5.1 mcg) a day, well short of 600 IU.
• In 67 healthy men followed through a Nebraska winter, blood vitamin D rose in step with the daily dose, and most of their winter need came from vitamin D stored from summer sun (Heaney et al., 2003).
• Men's adequate intake of vitamin K is 120 mcg a day, higher than the 90 mcg set for women (NIH ODS: Vitamin K).
• Age-related bone loss happens in men too, and men's fracture risk tends to rise about 5 to 10 years later than women's (NIH ODS: Calcium).

Why Vitamin D Matters for Men

Vitamin D is a fat-soluble vitamin your skin makes from sunlight. Its best known job is helping the gut absorb calcium and keeping calcium and phosphate levels steady in the blood, which the body needs to build and remodel bone (NIH ODS: Vitamin D). Your muscles need vitamin D to move, and your immune system needs it to work normally (NIH ODS: Vitamin D for consumers).

Age-related bone loss also happens in men; it simply shows up later, with fracture risk in older men rising about 5 to 10 years after it does in women (NIH ODS: Calcium). In studies of older men and postmenopausal women, vitamin D taken with calcium led to small increases in bone mineral density throughout the skeleton (NIH ODS: Vitamin D). For the women's side, see our sister guide, vitamin D for women.

How Much Vitamin D, Calcium and K2 Men Need

These are the official daily amounts for men, from food and supplements combined (NIH ODS: Vitamin D; NIH ODS: Calcium; NIH ODS: Vitamin K):

Age	Vitamin D a day	Calcium a day	Vitamin K a day
19 to 50	600 IU (15 mcg)	1,000 mg	120 mcg
51 to 70	600 IU (15 mcg)	1,000 mg	120 mcg
Over 70	800 IU (20 mcg)	1,200 mg	120 mcg
Upper limit	4,000 IU (100 mcg)	2,500 mg to 50; 2,000 mg from 51	None set

Two differences from women stand out. Men's calcium target stays at 1,000 mg until 70, while women's rises at 51. And men's adequate intake for vitamin K is 120 mcg, compared with 90 mcg for women.

Why Many Men Run Low

Few foods contain much vitamin D. In national survey data, men's average intake from food was about 204 IU (5.1 mcg) a day, against a target of 600 IU (NIH ODS: Vitamin D). Men tend to have slightly higher blood levels than women, but average levels in men drifted slightly lower over time while women's did not. Men most likely to fall short include:

• Older men: the skin makes vitamin D less efficiently with age, and older adults tend to spend more time indoors.
• Men with limited sun: indoor work, covered skin and long winters all cut how much the skin makes.
• Men with darker skin: more melanin means less vitamin D from the same sunlight.
• Men with a BMI of 30 or more: blood levels tend to run lower, and more vitamin D may be needed to reach the same level.
• Men who absorb fat poorly: vitamin D absorption depends on the gut's ability to absorb dietary fat.

What a winter study in men found

In a study of 67 healthy men in Omaha, Nebraska, researchers gave 0, 1,000, 5,000 or 10,000 IU of vitamin D3 a day for about 20 weeks over winter (the two highest doses are above the 4,000 IU upper limit and were given under study supervision). Blood levels rose in direct proportion to the dose, by about 0.7 nmol/L for each extra mcg (40 IU) a day. The authors estimated that healthy men use about 3,000 to 5,000 IU of vitamin D a day from all sources, and that more than 80 percent of their winter need came from vitamin D stored from summer sun (Heaney et al., 2003). By that slope, 1,000 IU a day would lift blood levels by roughly 17.5 nmol/L (about 7 ng/mL) once they settle. The practical point: summer stores run down over winter, so steady daily intake matters most in the darker months. Our vitamin D3 ingredient guide covers sunlight and food in more detail.

Vitamin D3 and K2 for Men: Why the Pair

Vitamin D raises how much calcium you absorb. Vitamin K is the cofactor for a process called gamma-carboxylation, which switches on proteins such as osteocalcin in bone and matrix Gla protein in the smooth muscle of blood vessels (NIH ODS: Vitamin K). Vitamin K2, the menaquinones, comes mainly from fermented foods, with natto the richest source, and in modest amounts from meat, dairy and eggs.

In a dose-finding trial, 42 healthy Dutch men and women aged 18 to 45 took a placebo or MK-7, a form of K2, at 10 to 360 mcg a day. Doses around the recommended daily amount increased the carboxylation, or activation, of both osteocalcin and matrix Gla protein, with no effect on thrombin generation, a blood clotting measure (Theuwissen et al., 2012). Both vitamins are fat-soluble, so one meal suits both. Our guides to vitamin D3 and K2 and vitamin K2: MK-4 vs MK-7 go deeper on the forms; MK-7 has a longer half-life than vitamin K1 (NIH ODS: Vitamin K).

How to Take Vitamin D3 and K2

• With a meal that has some fat: both vitamins are fat-soluble, so eggs, fish, nuts, yogurt or olive oil help.
• At the same time every day: tie it to a meal you never skip. Our guide to the best time to take vitamin D covers morning versus night.
• Count every source: multivitamins and fortified foods add up toward the 4,000 IU upper limit.
• Test if you want certainty: a blood level of 20 ng/mL (50 nmol/L) or more is generally adequate, and levels above 50 ng/mL (125 nmol/L) are higher than needed (NIH ODS: Vitamin D).
• Pick D3: at everyday doses D2 and D3 work about the same, but at high doses D2 is less potent.

Choosing vitamin D drops

If you are comparing vitamin D3 drops, look for D3 rather than D2, K2 in the same bottle, an oil base for a fat-soluble vitamin, third-party tested ingredients and a daily amount that keeps your total under 4,000 IU. Our guide to the best vitamin D3 and K2 supplement walks through each point. Strength training helps too; see creatine for men.

Is Vitamin D3 and K2 Safe for Men?

Most people tolerate vitamin D well at everyday doses, and sunlight alone does not cause too much. Very high supplement doses over time can push blood levels far above the normal range, which can cause nausea, vomiting, muscle weakness, confusion, loss of appetite and dehydration (NIH ODS: Vitamin D for consumers). Staying under the 4,000 IU upper limit from all sources keeps you clear of that. For vitamin K, no adverse effects from food or supplements have been reported (NIH ODS: Vitamin K).

The one group who must check first: anyone on warfarin or another blood thinner should talk with their clinician before starting vitamin K2, since people on these medicines need a consistent vitamin K intake. If you take any other prescription medicine, check with your clinician too.

Where Our Vitamin D3 + K2 Drops Fit

Our Vitamin D3 + K2 Drops put both vitamins in one drop: vegan vitamin D3 (cholecalciferol) from lichen with vitamin K2 as both MK-4 and MK-7, in MCT oil with sunflower vitamin E, made with third-party tested ingredients. Take 1 drop a day with a meal that has some fat. If you also want the minerals that work alongside vitamin D, our Vitamin D Cofactor Capsules are coming soon, with magnesium 100 mg and zinc 10 mg as bisglycinate and boron 3 mg as glycinate per 2 capsules; you can join the waitlist on the product page. Our immune system guide covers how vitamin D fits into daily immune support.

Benefits build with consistent daily use: months 1 to 2 can bring early changes, and 3 months and beyond is where the full benefit builds.

Frequently Asked Questions

How much vitamin D3 and K2 per day for a man?

The vitamin D target is 600 IU (15 mcg) a day up to 70 and 800 IU (20 mcg) after, with a 4,000 IU upper limit. Men's adequate intake for vitamin K is 120 mcg a day, and K2 doses around the recommended amount activated osteocalcin in a trial of healthy adults.

What are the benefits of vitamin D3 and K2 for men?

Vitamin D helps absorb calcium and supports bones, muscles and normal immune function. K2 activates osteocalcin, which binds calcium into bone, so the two work as a pair.

Should men take vitamin D with K2?

Many do. Both are fat-soluble, so they suit the same meal, and K2 activates the bone protein that uses the calcium vitamin D helps you absorb.

Are vitamin D3 drops good for men?

Drops make a small, steady daily amount easy, and an oil base suits a fat-soluble vitamin. Take them with a meal that has some fat.

What are the best vitamin D drops for men?

Look for D3 rather than D2, K2 in the same bottle, an oil base, third-party tested ingredients and a daily amount that keeps your total under 4,000 IU.

How much vitamin D should a man over 50 take?

600 IU (15 mcg) a day until 70, then 800 IU (20 mcg). Skin makes less vitamin D with age.

What vitamin D level should a man have?

A blood level of 20 ng/mL (50 nmol/L) or more is generally adequate, and above 50 ng/mL (125 nmol/L) is higher than needed.

Can men take too much vitamin D?

Yes, from very high supplement doses over time. Keep your total from all sources under 4,000 IU a day unless your clinician advises otherwise.

Sources

• National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
• National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Consumers. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
• National Institutes of Health, Office of Dietary Supplements. Calcium: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
• National Institutes of Health, Office of Dietary Supplements. Vitamin K: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
• Heaney RP, et al. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. American Journal of Clinical Nutrition, 2003. https://pubmed.ncbi.nlm.nih.gov/12499343/
• Theuwissen E, et al. Low-dose menaquinone-7 supplementation improved extra-hepatic vitamin K status, but had no effect on thrombin generation in healthy subjects. British Journal of Nutrition, 2012. https://pubmed.ncbi.nlm.nih.gov/22289649/

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.