Vitamin D3 is crucial for overall health, and understanding the right dosage is essential. According to HOW.EDU.VN, the recommended daily intake varies based on age, lifestyle, and health conditions, but generally, men need adequate vitamin D3 for bone health, immune function, and more. Ensuring sufficient levels can be achieved through diet, supplements, and sunlight exposure, contributing to optimal wellness. For personalized advice on “How Much Vitamin D3 Per Day For A Man,” consult with our team of experts at HOW.EDU.VN to determine the ideal dosage and supplementation strategies, including ergocalciferol and cholecalciferol options, while maintaining adequate serum calcium levels.
1. Understanding Vitamin D3: An Overview
Vitamin D, also known as calciferol, is a fat-soluble vitamin naturally present in limited foods, added to others, and available as a dietary supplement. It’s also produced when ultraviolet (UV) rays from sunlight strike the skin, triggering vitamin D synthesis. This vitamin is essential for many bodily functions, especially in men.
Vitamin D obtained from sun exposure, foods, and supplements is biologically inactive and needs two hydroxylations in the body to activate. The first occurs in the liver, converting vitamin D to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. The second hydroxylation happens primarily in the kidney, forming the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol [1].
1.1. Key Roles of Vitamin D3 in the Body
Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal bone mineralization and prevent hypocalcemic tetany. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts [1-3]. Without enough vitamin D, bones can become thin, brittle, or misshapen. Sufficient vitamin D prevents rickets in children and osteomalacia in adults. Together with calcium, it helps protect older adults from osteoporosis.
Vitamin D also plays roles in reducing inflammation and modulating cell growth, neuromuscular and immune function, and glucose metabolism [1-3]. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. Many tissues have vitamin D receptors, and some convert 25(OH)D to 1,25(OH)2D.
1.2. Vitamin D2 vs. Vitamin D3: What’s the Difference?
In foods and dietary supplements, vitamin D has two main forms: D2 (ergocalciferol) and D3 (cholecalciferol), which differ chemically only in their side-chain structures. Both forms are well absorbed in the small intestine through simple passive diffusion and a mechanism that involves intestinal membrane carrier proteins [4]. The concurrent presence of fat in the gut enhances vitamin D absorption, but some vitamin D is absorbed even without dietary fat. Neither aging nor obesity alters vitamin D absorption from the gut [4].
1.3. Measuring Vitamin D Status: Serum 25(OH)D
Serum concentration of 25(OH)D is the primary indicator of vitamin D status, reflecting vitamin D produced endogenously and that obtained from foods and supplements [1]. In serum, 25(OH)D has a fairly long circulating half-life of 15 days [1]. Serum concentrations of 25(OH)D are reported in nanomoles per liter (nmol/L) and nanograms per milliliter (ng/mL). One nmol/L is equal to 0.4 ng/mL, and 1 ng/mL is equal to 2.5 nmol/L.
Assessing vitamin D status by measuring serum 25(OH)D concentrations is complicated by the variability of available assays used by laboratories [5,6]. This variability can lead to falsely low or high results, depending on the assay and the laboratory. The international Vitamin D Standardization Program has developed procedures for standardizing the laboratory measurement of 25(OH)D to improve clinical and public health practice [5,7-10].
Circulating 1,25(OH)2D is generally not a good indicator of vitamin D status because it has a short half-life measured in hours, and serum levels are tightly regulated by parathyroid hormone, calcium, and phosphate [1]. Levels of 1,25(OH)2D do not typically decrease until vitamin D deficiency is severe [2].
1.4. Optimal Serum Concentrations for Health
Researchers have not definitively identified serum concentrations of 25(OH)D associated with deficiency, adequacy for bone health, and overall health. An expert committee of the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine (NASEM) concluded that people are at risk of vitamin D deficiency at serum 25(OH)D concentrations less than 30 nmol/L (12 ng/mL; see Table 1 for definitions of deficiency and inadequacy) [1]. Some people are potentially at risk of inadequacy at 30 to 50 nmol/L (12–20 ng/mL). Levels of 50 nmol/L (20 ng/mL) or more are sufficient for most people. The FNB committee also noted that serum concentrations greater than 125 nmol/L (50 ng/mL) can be associated with adverse effects [1] (Table 1). The Endocrine Society has not identified 25(OH)D concentrations associated with vitamin D sufficiency, insufficiency, and deficiency and does not recommend routine testing of 25(OH)D concentrations in healthy individuals [11,12].
Table 1: Serum 25-Hydroxyvitamin D [25(OH)D] Concentrations and Health [1]
| nmol/L* | ng/mL* | Health status |
|---|---|---|
| <30 | <12 | Associated with vitamin D deficiency, which can lead to rickets in infants and children and osteomalacia in adults |
| 30 to 50 | 12 to 20 | Generally considered inadequate for bone and overall health in healthy individuals |
| ≥50 | ≥20 | Generally considered adequate for bone and overall health in healthy individuals |
| >125 | >50 | Linked to potential adverse effects, particularly at >150 nmol/L (>60 ng/mL) |
*Serum concentrations of 25(OH)D are reported in both nanomoles per liter (nmol/L) and nanograms per milliliter (ng/mL). One nmol/L = 0.4 ng/mL, and 1 ng/mL = 2.5 nmol/L. Optimal serum concentrations of 25(OH)D for bone and general health have not been established because they are likely to vary by stage of life, by race and ethnicity, and with each physiological measure used [1,13,14]. In addition, although 25(OH)D levels rise in response to increased vitamin D intake, the relationship is nonlinear [1]. The amount of increase varies, for example, by baseline serum levels and duration of supplementation.
2. Recommended Vitamin D3 Intake for Men
Understanding the recommended daily intakes of vitamin D3 is essential for maintaining optimal health. The Dietary Reference Intakes (DRIs) developed by expert committees of NASEM provide guidelines for planning and assessing nutrient intakes of healthy people [1]. These values vary by age and sex and include the Recommended Dietary Allowance (RDA), Adequate Intake (AI), Estimated Average Requirement (EAR), and Tolerable Upper Intake Level (UL).
2.1. Understanding DRIs for Vitamin D3
- Recommended Dietary Allowance (RDA): The average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals. This is often used to plan nutritionally adequate diets for individuals.
- Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy, established when evidence is insufficient to develop an RDA.
- Estimated Average Requirement (EAR): The average daily level of intake estimated to meet the requirements of 50% of healthy individuals. This is typically used to assess nutrient intakes of groups of people and plan nutritionally adequate diets for them; it can also be used to assess the nutrient intakes of individuals.
- Tolerable Upper Intake Level (UL): The maximum daily intake unlikely to cause adverse health effects.
An FNB committee established RDAs for vitamin D to indicate daily intakes sufficient to maintain bone health and normal calcium metabolism in healthy people. RDAs for vitamin D are listed in both micrograms (mcg) and International Units (IU); 1 mcg vitamin D is equal to 40 IU (Table 2). Even though sunlight is a major source of vitamin D for some people, the FNB based the vitamin D RDAs on the assumption that people receive minimal sun exposure [1]. For infants, the FNB committee developed AIs based on the amount of vitamin D that maintains serum 25(OH)D levels above 20 ng/mL (50 nmol/L) and supports bone development.
Table 2: Recommended Dietary Allowances (RDAs) for Vitamin D [1]
| Age | Male | Female | Pregnancy | Lactation |
|---|---|---|---|---|
| 0-12 months* | 10 mcg (400 IU) | 10 mcg (400 IU) | ||
| 1–13 years | 15 mcg (600 IU) | 15 mcg (600 IU) | ||
| 14–18 years | 15 mcg (600 IU) | 15 mcg (600 IU) | 15 mcg (600 IU) | 15 mcg (600 IU) |
| 19–50 years | 15 mcg (600 IU) | 15 mcg (600 IU) | 15 mcg (600 IU) | 15 mcg (600 IU) |
| 51–70 years | 15 mcg (600 IU) | 15 mcg (600 IU) | ||
| >70 years | 20 mcg (800 IU) | 20 mcg (800 IU) |
*Adequate Intake (AI)
2.2. Variations in Global Guidelines
Many other countries and some professional societies have somewhat different guidelines for vitamin D intakes [15]. These differences result from an incomplete understanding of the biology and clinical implications of vitamin D, different purposes for the guidelines (e.g., for public health in a healthy population or for clinical practice), and the use of observational studies in addition to randomized clinical trials to establish recommendations [9,15]. For example, the United Kingdom Scientific Advisory Committee on Nutrition recommends intakes of 10 mcg (400 IU)/day for individuals age 4 years and older [16]. The Endocrine Society recommends routine vitamin D supplementation for children and teens age 1 to 18 years, people who are pregnant, adults with pre-diabetes, and adults age 75 years and older, but not for healthy adults age 19 to 74 [11,12]. The Endocrine Society does not recommend specific doses but notes that all individuals should adhere to the RDA.
2.3. Factors Influencing Individual Vitamin D3 Needs
Several factors can influence an individual’s vitamin D3 needs:
- Age: As men age, their skin’s ability to synthesize vitamin D declines, and they may spend more time indoors.
- Skin pigmentation: Darker skin requires more sun exposure to produce the same amount of vitamin D as lighter skin.
- Geographic location: Those living in northern latitudes receive less sunlight, especially during winter months.
- Lifestyle: Indoor lifestyles, clothing habits, and sunscreen use can limit sun exposure and vitamin D synthesis.
- Medical conditions: Certain conditions like obesity, liver disease, cystic fibrosis, celiac disease, Crohn’s disease, and ulcerative colitis can affect vitamin D absorption and metabolism.
- Medications: Certain medications, such as orlistat, statins, steroids, and thiazide diuretics, can interfere with vitamin D levels.
These factors emphasize the importance of consulting with healthcare professionals at HOW.EDU.VN to tailor vitamin D3 intake recommendations to individual needs, ensuring optimal health outcomes and preventing deficiencies or toxicities.
3. Sources of Vitamin D3 for Men
Ensuring adequate vitamin D intake can be achieved through various sources, including food, sun exposure, and dietary supplements. Understanding these sources helps men make informed choices about their vitamin D intake.
3.1. Dietary Sources: Foods Rich in Vitamin D3
Few foods naturally contain vitamin D. The flesh of fatty fish (such as trout, salmon, tuna, and mackerel) and fish liver oils are among the best sources [17,1]. An animal’s diet affects the amount of vitamin D in its tissues. Beef liver, egg yolks, and cheese have small amounts of vitamin D, primarily in the form of vitamin D3 and its metabolite 25(OH)D3. Mushrooms provide variable amounts of vitamin D2 [17]. Some mushrooms available on the market have been treated with UV light to increase their levels of vitamin D2. In addition, the Food and Drug Administration (FDA) has approved UV-treated mushroom powder as a food additive for use as a source of vitamin D2 in food products [18]. Very limited evidence suggests no substantial differences in the bioavailability of vitamin D from various foods [19].
Animal-based foods typically provide some vitamin D in the form of 25(OH)D in addition to vitamin D3. The impact of this form on vitamin D status is an emerging area of research. Studies show that 25(OH)D appears to be approximately five times more potent than the parent vitamin for raising serum 25(OH)D concentrations [17,20,21]. One study found that when the 25(OH)D content of beef, pork, chicken, turkey, and eggs is taken into account, the total amount of vitamin D in the food is 2 to 18 times higher than the amount in the parent vitamin alone, depending on the food [20].
Fortified foods provide most of the vitamin D in American diets [1,22]. For example, almost all of the U.S. milk supply is voluntarily fortified with about 3 mcg/cup (120 IU), usually in the form of vitamin D3 [23]. In Canada, milk must be fortified with 0.88–1.0 mcg/100 mL (35–40 IU), and the required amount for margarine is at least 13.25 mcg/100 g (530 IU). Other dairy products made from milk, such as cheese and ice cream, are not usually fortified in the United States or Canada. Plant milk alternatives (such as beverages made from soy, almond, or oats) are often fortified with similar amounts of vitamin D to those in fortified cow’s milk (about 3 mcg [120 IU]/cup); the Nutrition Facts label lists the actual amount [24]. Ready-to-eat breakfast cereals often contain added vitamin D, as do some brands of orange juice, yogurt, margarine, and other food products.
The United States mandates the fortification of infant formula with 1–2.5 mcg/100 kcal (40–100 IU) vitamin D; 1–2 mcg/100 kcal (40–80 IU) is the required amount in Canada [1].
Table 3: Vitamin D Content of Selected Foods [25]
| Food | Micrograms (mcg) per serving | International Units (IU) per serving | Percent DV* |
|---|---|---|---|
| Cod liver oil, 1 tablespoon | 34.0 | 1,360 | 170 |
| Trout (rainbow), farmed, cooked, 3 ounces | 16.2 | 645 | 81 |
| Salmon (sockeye), cooked, 3 ounces | 14.2 | 570 | 71 |
| Mushrooms, white, raw, sliced, exposed to UV light, ½ cup | 9.2 | 366 | 46 |
| Milk, 2% milkfat, vitamin D fortified, 1 cup | 2.9 | 120 | 15 |
| Soy, almond, and oat milks, vitamin D fortified, various brands, 1 cup | 2.5–3.6 | 100–144 | 13–18 |
| Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 1 serving | 2.0 | 80 | 10 |
| Sardines (Atlantic), canned in oil, drained, 2 sardines | 1.2 | 46 | 6 |
| Egg, 1 large, scrambled** | 1.1 | 44 | 6 |
| Liver, beef, braised, 3 ounces | 1.0 | 42 | 5 |
| Tuna fish (light), canned in water, drained, 3 ounces | 1.0 | 40 | 5 |
| Cheese, cheddar, 1.5 ounce | 0.4 | 17 | 2 |
| Mushrooms, portabella, raw, diced, ½ cup | 0.1 | 4 | 1 |
| Chicken breast, roasted, 3 ounces | 0.1 | 4 | 1 |
| Beef, ground, 90% lean, broiled, 3 ounces | 0 | 1.7 | 0 |
| Broccoli, raw, chopped, ½ cup | 0 | 0 | 0 |
| Carrots, raw, chopped, ½ cup | 0 | 0 | 0 |
| Almonds, dry roasted, 1 ounce | 0 | 0 | 0 |
| Apple, large | 0 | 0 | 0 |
| Banana, large | 0 | 0 | 0 |
| Rice, brown, long-grain, cooked, 1 cup | 0 | 0 | 0 |
| Whole wheat bread, 1 slice | 0 | 0 | 0 |
| Lentils, boiled, ½ cup | 0 | 0 | 0 |
| Sunflower seeds, roasted, ½ cup | 0 | 0 | 0 |
| Edamame, shelled, cooked, ½ cup | 0 | 0 | 0 |
* DV = Daily Value. The FDA developed DVs to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet. The DV for vitamin D is 20 mcg (800 IU) for adults and children age 4 years and older [26]. The labels must list vitamin D content in mcg per serving and have the option of also listing the amount in IUs in parentheses. Foods providing 20% or more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet. ** Vitamin D is in the yolk.
3.2. Sunlight Exposure: How Much is Enough?
Most people in the world meet at least some of their vitamin D needs through exposure to sunlight [1]. Type B UV (UVB) radiation with a wavelength of approximately 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. Season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. Older people and people with dark skin are less able to produce vitamin D from sunlight [1]. UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D [27].
The factors that affect UV radiation exposure, individual responsiveness, and uncertainties about the amount of sun exposure needed to maintain adequate vitamin D levels make it difficult to provide guidelines on how much sun exposure is required for sufficient vitamin D synthesis [15,28]. Some expert bodies and vitamin D researchers suggest, for example, that approximately 5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., either daily or at least twice a week to the face, arms, hands, and legs without sunscreen usually leads to sufficient vitamin D synthesis [13,15,28]. Moderate use of commercial tanning beds that emit 2% to 6% UVB radiation is also effective [13,29].
However, despite the importance of the sun for vitamin D synthesis, limiting skin exposure to sunlight and UV radiation from tanning beds is prudent [28]. UV radiation is a carcinogen, and UV exposure is the most preventable cause of skin cancer. Federal agencies and national organizations advise taking photoprotective measures to reduce the risk of skin cancer, including using sunscreen with a sun protection factor (SPF) of 15 or higher, whenever people are exposed to the sun [28,30]. Sunscreens with an SPF of 8 or more appear to block vitamin D-producing UV rays. In practice, however, people usually do not apply sufficient amounts of sunscreen, cover all sun-exposed skin, or reapply sunscreen regularly. Their skin probably synthesizes some vitamin D, even with typically applied sunscreen amounts [1,28].
3.3. Vitamin D3 Supplements: Types and Considerations
Dietary supplements can contain vitamins D2 or D3. Vitamin D2 is manufactured using UV irradiation of ergosterol in yeast, and vitamin D3 is typically produced with irradiation of 7-dehydrocholesterol from lanolin obtained from the wool of sheep [13,31]. An animal-free version of vitamin D3 sourced from lichen is also available [32]. People who avoid all animal-sourced products can contact dietary supplement manufacturers to ask about their sourcing and processing techniques.
Both vitamins D2 and D3 raise serum 25(OH)D levels, and they seem to have equivalent ability to cure rickets [4]. In addition, most steps in the metabolism and actions of vitamins D2 and D3 are identical. However, most evidence indicates that vitamin D3 increases serum 25(OH)D levels to a greater extent and maintains these higher levels longer than vitamin D2, even though both forms are well absorbed in the gut [33-36].
Some studies have used dietary supplements containing the 25(OH)D3 form of vitamin D. Per equivalent microgram dose, 25(OH)D3 is three to five times as potent as vitamin D3 [37,38]. However, no 25(OH)D3 dietary supplements appear to be available to consumers on the U.S. market at this time [32].
Men can leverage these sources by incorporating fatty fish and fortified foods into their diet, spending short periods in the sun without excessive protection, and considering vitamin D3 supplements, especially during winter or when sun exposure is limited. Consulting with healthcare professionals at HOW.EDU.VN ensures a balanced approach, tailored to individual needs and health conditions, optimizing vitamin D levels and overall health.
4. Vitamin D3 Deficiency in Men: Risks and Symptoms
Understanding the risks and symptoms of vitamin D deficiency is crucial for men to take proactive steps in maintaining their health. Vitamin D deficiency can arise from inadequate intake, limited sun exposure, impaired conversion of 25(OH)D to its active form by the kidneys, or inadequate absorption from the digestive tract.
4.1. Common Causes of Vitamin D3 Deficiency
People can develop vitamin D deficiency when usual intakes are lower over time than recommended levels, exposure to sunlight is limited, the kidneys cannot convert 25(OH)D to its active form, or absorption of vitamin D from the digestive tract is inadequate. Diets low in vitamin D are more common in people who have milk allergy or lactose intolerance and those who consume an ovo-vegetarian or vegan diet [1].
4.2. Signs and Symptoms of Vitamin D3 Deficiency in Men
In adults and adolescents, vitamin D deficiency can lead to osteomalacia, in which existing bone is incompletely or defectively mineralized during the remodeling process, resulting in weak bones [46]. Signs and symptoms of osteomalacia are similar to those of rickets and include bone deformities and pain, hypocalcemic seizures, tetanic spasms, and dental abnormalities [45].
Common symptoms of vitamin D deficiency in men include:
- Fatigue and weakness
- Bone pain or tenderness
- Muscle weakness or cramps
- Increased susceptibility to infections
- Mood changes, such as depression
4.3. Health Risks Associated with Deficiency
Vitamin D deficiency can lead to several health risks for men, including:
- Osteoporosis: Insufficient vitamin D contributes to osteoporosis by reducing calcium absorption, leading to decreased bone density and increased fracture risk [1].
- Increased risk of falls: Vitamin D deficiency can affect muscle strength and lead to muscle weakness, increasing the risk of falls, particularly in older adults [1].
- Cardiovascular issues: Deficiency is associated with vascular dysfunction, arterial stiffening, left ventricular hypertrophy, and hyperlipidemia [121].
- Increased cancer risk: Some observational studies suggest a link between low vitamin D levels and increased risks of certain cancers [88].
- Immune dysfunction: Vitamin D plays a role in immune function, and deficiency can increase susceptibility to infections [1-3].
- Depression: Low vitamin D levels have been associated with depression [133].
4.4. Screening and Testing for Vitamin D3 Levels
Screening for vitamin D status is becoming a more common part of routine laboratory bloodwork ordered by primary-care physicians, irrespective of any indications for this practice [6,52-54]. No studies have examined whether such screening for vitamin D deficiency results in improved health outcomes [55]. The U.S. Preventive Services Task Force (USPSTF) found insufficient evidence to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults [6]. It added that no national professional organization recommends population screening for vitamin D deficiency.
Despite the USPSTF’s findings, monitoring vitamin D levels through serum 25(OH)D testing can be beneficial for individuals at high risk of deficiency. Consulting with healthcare professionals at HOW.EDU.VN can help determine if testing is necessary and what steps should be taken based on the results. Early detection and management of vitamin D deficiency can prevent serious health complications and improve overall well-being.
5. Groups at Risk of Vitamin D3 Inadequacy
Several groups of men are at an increased risk of developing vitamin D inadequacy. Recognizing these groups and understanding their specific needs is essential for targeted interventions and personalized healthcare.
5.1. Older Adults
Older adults are at increased risk of developing vitamin D insufficiency, partly because the skin’s ability to synthesize vitamin D declines with age [1,61]. In addition, older adults are likely to spend more time than younger people indoors, and they might have inadequate dietary intakes of the vitamin [1]. This combination of factors makes older men particularly vulnerable to vitamin D deficiency.
5.2. Individuals with Limited Sun Exposure
Homebound individuals; people who wear long robes, dresses, or head coverings for religious reasons; and people with occupations that limit sun exposure are among the groups that are unlikely to obtain adequate amounts of vitamin D from sunlight [62]. The use of sunscreen also limits vitamin D synthesis from sunlight. However, because the extent and frequency of sunscreen use are unknown, the role that sunscreen may play in reducing vitamin D synthesis is unclear [1].
5.3. People with Dark Skin
Greater amounts of the pigment melanin in the epidermal layer of the skin result in darker skin and reduce the skin’s ability to produce vitamin D from sunlight [1]. Black Americans, for example, typically have lower serum 25(OH)D levels than White Americans. However, whether these lower levels in persons with dark skin have significant health consequences is not clear [14]. Those of African American ancestry, for example, have lower rates of bone fracture and osteoporosis than do Whites (see the section below on bone health and osteoporosis).
5.4. Individuals with Conditions Limiting Fat Absorption
Because vitamin D is fat soluble, its absorption depends on the gut’s ability to absorb dietary fat [4]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn’s disease, and ulcerative colitis [1,63]. In addition to having an increased risk of vitamin D deficiency, people with these conditions might not eat certain foods, such as dairy products (many of which are fortified with vitamin D), or eat only small amounts of these foods. Individuals who have difficulty absorbing dietary fat might therefore require vitamin D supplementation [63].
5.5. People with Obesity or Who Have Undergone Gastric Bypass Surgery
Individuals with a body mass index (BMI) of 30 or more have lower serum 25(OH)D levels than individuals without obesity. Obesity does not affect the skin’s capacity to synthesize vitamin D. However, greater amounts of subcutaneous fat sequester more of the vitamin [1]. People with obesity might need greater intakes of vitamin D to achieve 25(OH)D levels similar to those of people with normal weight [1,64,65].
Individuals with obesity who have undergone gastric bypass surgery can also become vitamin D deficient. In this procedure, part of the upper small intestine, where vitamin D is absorbed, is bypassed, and vitamin D that is mobilized into the bloodstream from fat stores might not raise 25(OH)D to adequate levels over time [66,67]. Various expert groups—including the American Association of Metabolic and Bariatric Surgery, The Obesity Society, and the British Obesity and Metabolic Surgery Society—have developed guidelines on vitamin D screening, monitoring, and replacement before and after bariatric surgery [66,[68]].
Identifying and addressing the specific needs of these at-risk groups is essential. how.edu.vn offers personalized consultations with healthcare professionals who can assess individual risk factors and provide tailored recommendations for vitamin D intake and supplementation. Regular monitoring and appropriate interventions can help prevent deficiency and promote optimal health outcomes.
6. Health Benefits of Adequate Vitamin D3 Levels in Men
Maintaining adequate vitamin D3 levels is essential for various aspects of men’s health. From bone strength to immune function and chronic disease prevention, vitamin D3 plays a crucial role in overall well-being.
6.1. Bone Health and Osteoporosis Prevention
Bone health also depends on support from the surrounding muscles to assist with balance and postural sway and thereby reduce the risk of falling. Vitamin D is also needed for the normal development and growth of muscle fibers. In addition, inadequate vitamin D levels can adversely affect muscle strength and lead to muscle weakness and pain (myopathy) [1].
6.1.1. Clinical Trial Evidence on Older Adults
Among postmenopausal women and older men, many clinical trials have shown that supplements of both vitamin D and calcium result in small increases in bone mineral density throughout the skeleton [1,74]. They also help reduce fracture rates in institutionalized older people. However, the evidence on the impact of vitamin D and calcium supplements on fractures in community-dwelling individuals is inconsistent.
The USPSTF evaluated 11 randomized clinical trials of vitamin D and/or calcium supplementation in a total of 51,419 healthy, community-dwelling adults age 50 years and older who did not have osteoporosis, vitamin D deficiency, or prior fractures [75,76]. It concluded that the current evidence was insufficient to evaluate the benefits and harms of supplementation to prevent fractures. In addition, the USPSTF recommended against supplementation with 10 mcg (400 IU) or less of vitamin D and 1,000 mg or less of calcium to prevent fractures in this population, but it could not determine the balance of benefits and harms from higher doses.
6.1.2. Vitamin D Supplements for Bone Health in Minority Populations
Bone mineral density, bone mass, and fracture risk are correlated with serum 25(OH)D levels in White Americans and Mexican Americans, but not in Black Americans [14,83]. Factors such as adiposity, skin pigmentation, vitamin D binding protein polymorphisms, and genetics contribute to differences in 25(OH)D levels between Black and White Americans.
One clinical trial randomized 260 Black women age 60 years and older (mean age 68.2 years) to receive 60 to 120 mcg (2,400 to 4,800 IU) per day vitamin D3 supplementation to maintain serum 25(OH)D levels above 75 nmol/L (30 ng/mL) for 3 years [84]. The results showed no association between 25(OH)D levels or vitamin D dose and the risk of falling in the 184 participants who completed the study. In fact, Black Americans might have a greater risk than White Americans of falls and fractures with daily vitamin D intakes of 50 mcg (2,000 IU) or more [14]. Furthermore, the bone health of older Black American women does not appear to benefit from raising serum 25(OH)D levels beyond 50 nmol/L (20 ng/mL) [84].
6.1.3. Vitamin D Supplements and Muscle Function
Studies examining the effects of supplemental vitamin D on muscle strength and on rate of decline in muscle function have had inconsistent results [55]. One recent clinical trial, for example, randomized 78 frail and near-frail adults age 65 years and older to receive 20 mcg (800 IU) vitamin D
