Best 8 Vitamin D3 Supplements for Women: What the Science Says

Vitamin D may support many aspects of women’s health, including bone strength, hormone regulation, immune function, and even mood. Yet, vitamin D deficiency remains widespread, especially among women with limited sun exposure or restrictive diets. This makes vitamin D supplements a practical way to help maintain optimal Vitamin D levels.

Vitamin D supplements can play a critical role in reducing that risk by helping the body maintain bone density and prevent fractures. These products could also support immune defense and contribute to hormonal balance by influencing levels of estrogen and progesterone, hormones that affect menstrual regularity, fertility, and reproductive health.

To help you choose the right one, we’ve reviewed and selected the 8 best vitamin D supplements for women in 2025 based on factors such as ingredient quality, dosage, form, and suitability for various fitness and dietary needs.

8 Best Vitamin D Supplements for Women In 2025

1. Thorne Vitamin D-1

   

   Thorne’s Vitamin D-1,000 formula provides 1,000 International Units (IU), or 25 micrograms (mcg), of vitamin D3 per capsule.

   Vitamin D3, also known as cholecalciferol, is the active form of vitamin D that the body produces when the skin is exposed to sunlight, specifically ultraviolet B (UVB) rays. This form is superior to vitamin D2 (ergocalciferol) in terms of potency and bioavailability, meaning it is more efficiently absorbed and utilized by your body.

   As per the official website, Thorne’s Vitamin D-1 is designed for easy absorption and contains hypoallergenic ingredients, such as hypromellose capsules (a vegetarian cellulose-based shell), and no common allergens like lactose or preservatives such as BHT or BHA. It also includes microcrystalline cellulose, leucine, silicon dioxide, and vitamin E (as d-alpha tocopheryl), which serve as stabilizers, anti-caking agents, and antioxidants, ensuring the product’s quality and longevity without compromising safety.

   The makers state that Thorne’s Vitamin D-1 capsules are third-party tested, which means their potency and purity have been verified independently to ensure that the product is free from contaminants such as pesticides, heavy metals, or microbial pathogens.

   According to the official website, Thorne’s Vitamin D-1 could support muscle function by promoting lean muscle mass and strength. It may also support muscle contraction and performance, which can decrease the chances of falls and fractures in older adults.
   

   Pros

   • Uses vitamin D3 (cholecalciferol), which is more potent and better absorbed than vitamin D2.
   • Provides 1,000 IU (25 mcg), covering 125% of the daily value per capsule.
   • Clean formula free from lactose, gluten, soy, and preservatives like BHT and BHA.
   • Vegetarian-friendly capsule made from hypromellose (cellulose-based).
   • Supports bone health, muscle strength, immune function, brain, and cardiovascular health.

   Cons

   • A 1,000 IU dose may be insufficient for those with significant deficiency or higher needs.
   • Capsule form might not suit those who prefer liquid or chewable supplements.
   • Does not include complementary nutrients like calcium or magnesium.

2. Micro Ingredients Vitamin D3 K2 Supplement Softgels

   

   The Vitamin D3 + K2 Supplement Softgels by Micro Ingredients combine two fat-soluble vitamins, such as Vitamin D3 (cholecalciferol) and Vitamin K2 (menaquinone-7, MK-7), which may help support bone, cardiovascular, and immune function.

   As per the official website, Vitamin D3 + K2 Supplement Softgels contain a potent dose of 10,000 IU of vitamin D3 and 200 mcg of vitamin K2, formulated with MCT coconut oil to boost absorption. These softgels are easy to take daily and are made with gelatin, glycerin, and purified water for enhanced bioavailability.

   Vitamin K2 (MK-7) in Vitamin D3 + K2 Supplement Softgels could help activate proteins such as osteocalcin, which directs calcium to bones for proper mineralization, and matrix Gla-protein (MGP), which helps prevent calcium buildup in arteries and soft tissues. This regulation reduces the risk of arterial calcification, a factor in cardiovascular disease.

   When combined, vitamins D3 and K2 work synergistically in this formula to ensure calcium is absorbed effectively and safely directed into bones, supporting joint health, bone strength, and heart function.
   

   Pros

   • Contains virgin coconut oil or sunflower oil to enhance the absorption of fat-soluble vitamins.
   • Softgels are small and easy to swallow, favored by users who dislike large pills.
   • Free from GMOs, soy, gluten, preservatives, artificial colors, and flavors.

   Cons

   • Some people may experience occasional side effects like headaches or stomach issues.
   • Packaging (resealable bag) can be tricky to open or may tear, affecting your experience.

3. Mary Ruth’s Megadose Liposomal

   

   MaryRuth Organics Megadose D3 Liposomal is a liquid formula that provides a potent dose of 4,000 IU (International Units) of vitamin D3 per teaspoon (5 mL serving). It could help regulate calcium metabolism, bone health, and immune function.

   As per the official website, MaryRuth Organics Megadose D3 Liposomal uses liposomal technology, where vitamin D3 is encapsulated in tiny lipid (fat) vesicles called liposomes. These liposomes protect vitamin D from digestive breakdown and improve its uptake through the intestinal walls, leading to greater bioavailability. This means more vitamin D3 reaches your bloodstream and can be utilized effectively.

   The makers state that MaryRuth Organics Megadose D3 Liposomal is free from common allergens and animal products, being vegan, dairy-free, gluten-free, soy-free, nut-free, and sugar-free.

   MaryRuth Organics Megadose D3 Liposomal could support calcium and phosphate homeostasis, essential minerals for healthy bones and teeth. It may help enhance intestinal absorption of calcium and phosphate and reduce their excretion via the kidneys, supporting proper bone mineralization and reducing risks of bone diseases like osteoporosis and rickets.

   According to the official website, MaryRuth Organics Megadose D3 Liposomal might also help modulate innate and adaptive immunity by influencing immune cells like macrophages and T-cells, boosting your body’s defense against infections while dampening chronic inflammatory responses that can cause tissue damage and autoimmune conditions. This immunomodulatory effect is vital in maintaining balanced immune health.

   The MaryRuth Organics Megadose D3 Liposomal formula includes 2.4 mcg of vitamin B12 (as methylcobalamin), providing 100% of the recommended daily intake. Vitamin B12 is critical for nerve function, RBC production, and DNA synthesis. Its presence complements the immune and neurological benefits of vitamin D3.
   

   Pros

   • Could help enhance absorption due to liposomal encapsulation technology.
   • The liquid form allows easy consumption directly or mixed with beverages.
   • Might help maintain normal gene expression and cellular functions.

   Cons

   • Requires refrigeration before and after opening for best quality.
   • Requires daily dosing, which may be inconvenient for some users.

4. Nature Made Vitamin D3 2000 IU

   

   As per the official website, Nature Made Vitamin D3 2000 IU (50 mcg) Tablets may support the health of the muscles, bones, teeth, and immune system. It could help your body absorb calcium from your intestines, which is necessary for building and maintaining strong bones and teeth. Nature Made Vitamin D3 2000 IU provides 2000 IU of vitamin D3 along with 90 mg of calcium from calcium carbonate. The formula is gluten-free, contains no artificial flavors or colors, and meets United States Pharmacopeia (USP) standards for quality, potency, and purity.
   

   Pros

   • One tablet daily dosage is convenient and easy to remember.
   • USP verified, ensuring high quality and purity standards.
   • May support muscle strength and reduce muscle fatigue.

   Cons

   • It might cause mild side effects such as stomach upset or allergic reactions in some users.
   • No flavoring may make tablets less palatable for some users.

5. NOW Foods Vitamin D-3 10

   

   According to the makers, NOW Foods Vitamin D-3 10,000 IU provides a high-potency vitamin D3 in convenient liquid softgel form for optimal absorption. It includes vitamin D3, sourced from lanolin, a natural extract from sheep’s wool. Vitamin D is fat-soluble, so NOW Foods Vitamin D-3 10,000 IU formulation includes extra virgin olive oil and safflower oil to enhance bioavailability and ensure efficient uptake in the digestive system.

   The official website states that NOW Foods Vitamin D-3 10,000 IU is non-GMO, gluten-free, soy-free, corn-free, dairy-free, egg-free, and sugar-free. It also holds Halal and Kosher certifications (contains bovine gelatin) and is manufactured in a GMP-certified facility, ensuring strict quality, potency, and safety standards.

   As per the makers, NOW Foods Vitamin D-3 10,000 IU includes BSE-free bovine gelatin, glycerin, and water, alongside the oils that support vitamin D absorption. It might help maintain healthy bones by improving calcium absorption, enhancing immune defense through vitamin D’s action on immune cells, and supporting muscle function to reduce fall risk.
   

   Pros

   • May support immune system function and may reduce infection risk.
   • Includes fat-soluble vitamin D-3 form, which is more bioavailable than D-2.
   • It is gluten, dairy, corn, and egg-free.

   Cons

   • High potency (10,000 IU) may lead to vitamin D toxicity if taken excessively or without medical supervision.
   • Some people may experience allergic reactions to softgel ingredients.

6. Garden Of Life Vitamin Code Raw Vitamin D3 Capsules

   

   Garden of Life claims that its Vitamin Code Raw Vitamin D3 provides a potent dose of 5,000 IU (125 mcg) of vitamin D3 in a raw, whole-food based supplement. This formula delivers vitamin D3 in a lipid-rich base derived from cracked wall chlorella, a type of green algae. This whole-food lipid base enhances the bioavailability of vitamin D3, a fat-soluble vitamin, by improving its absorption in the digestive tract.

   Vitamin Code Raw Vitamin D3 by Garden of Life comes encapsulated in vegetarian capsules without any binders, fillers, artificial additives, or synthetic ingredients, preserving the “raw” nature of the nutrients. This means the vitamins and cofactors are not exposed to high heat during processing, which helps retain the integrity of delicate enzymes, live probiotics, and cofactors naturally present in whole foods.

   The addition of live probiotics and digestive enzymes such as Lactobacillus bulgaricus and Lactobacillus plantarum in Vitamin Code Raw Vitamin D3, along with enzymes like lipase, protease, and cellulase, may support optimal digestion and nutrient absorption.

   As per the official website, Vitamin Code Raw Vitamin D3 also contains a blend of 23 organically grown powdered fruits and vegetables, including apples, beets, broccoli, carrots, spinach, and more. These plant-based ingredients provide antioxidants, vitamins, and phytonutrients that complement the vitamin D3 action.
   

   Pros

   • Vitamin D3 is available in a whole food lipid base of wall chlorella to enhance absorption.
   • Includes live probiotics and digestive enzymes that may support healthy digestion.
   • Non-GMO Project Verified.

   Cons

   • Capsule size may be inconvenient for some people to swallow.
   • Some people may find the pricing higher.

7. Life Extension Vitamins D And K With Sea-Iodine

   

   According to the official website, Life Extension’s Vitamins D and K with Sea-Iodine could support bone, brain, thyroid, immune, and cardiovascular health. It provides a high potency of 125 mcg (5,000 IU) of vitamin D3, which is known as the biologically active vitamin D produced in your skin upon exposure to UVB sunlight.

   Life Extension Vitamins D and K with Sea-Iodine also provide a total of 2,100 mcg of vitamin K, split among vitamin K1 (phytonadione) and two forms of vitamin K2 (menaquinone-4 and menaquinone-7).

   Vitamin K1 primarily supports blood clotting, while the K2 forms are critical regulators of calcium utilization in the body. Vitamin K2 activates proteins such as osteocalcin, which helps bind calcium to the bone matrix, thus improving bone mineral density, and matrix GLA protein, which may prevent calcium deposits in arteries and soft tissues, thereby protecting cardiovascular health by reducing arterial calcification. This balanced blend of K1 and K2 in Life Extension’s Vitamins D and K with Sea-Iodine may ensure that calcium absorbed with the aid of vitamin D3 is properly directed to bones rather than accumulating in blood vessels, which can lead to cardiovascular disease.

   The formula also contains 1,000 mcg of iodine derived from the Sea-Iodine™ complex, which combines organic kelp and bladderwrack seaweed extracts with potassium iodide to provide a natural and bioavailable iodine source. Iodine is an indispensable trace mineral necessary for synthesizing thyroid hormones thyroxine (T4) and triiodothyronine (T3), which regulate metabolic rate, growth, development, and energy production.
   

   Pros

   • Provides a high potency dose of 125 mcg (5,000 IU) of vitamin D3 per capsule.
   • Contains 2100 mcg of vitamin K, including K1 and two forms of K2 (MK-4 and MK-7).
   • Could support bone health by promoting calcium absorption into the bone matrix.

   Cons

   • May not be suitable for people allergic to seafood or seaweed-derived ingredients.
   • The iodine dose (1000 mcg) is relatively high and may cause thyroid issues in sensitive people.

8. Mindbodygreen Vitamin D3 Potency+

   

   Mindbodygreen’s vitamin D3 potency+ provides a potent 5,000 IU (125 mcg) of vitamin D3 per gel cap, sourced from organic algae using VegD3® technology. This plant-based, vegan vitamin D3 (cholecalciferol) is sustainably derived and is highly bioavailable, which means your body can efficiently absorb and utilize it.

   As per the official website, Mindbodygreen’s vitamin D3 potency+ is enhanced with organic flaxseed oil (250 mg), rich in alpha-linolenic acid (an omega-3 fatty acid, 137 mg per serving), organic avocado oil (250 mg), and organic extra virgin olive oil (250 mg) containing oleic acid (an omega-9 fatty acid, 287 mg per serving).

   Mindbodygreen’s vitamin D3 potency+ might support calcium metabolism, which is vital for maintaining strong bones and teeth by enhancing calcium absorption in your gut and helping regulate bone remodeling. It could also help modulate the immune system, influencing innate and adaptive immune responses to help your body defend against pathogens and maintain immune balance.
   

   Pros

   • Includes avocado, flaxseed, and olive oils to enhance absorption of fat-soluble vitamin D3.
   • Comes in a brown glass bottle that protects the contents from light degradation.
   • Contains no GMOs and is dairy and soy-free.

   Cons

   • Contains bovine gelatin capsules, making it unsuitable for vegans.
   • Packaging is recyclable, but it still involves glass bottles, which may be fragile or inconvenient for travel.

Side Effects Of Vitamin D Supplements

1. Hypercalcemia (High Blood Calcium Levels)

   One of the most common risks associated with high doses of vitamin D supplements is hypercalcemia or elevated calcium levels in the blood. Vitamin D might help your body with optimal calcium absorption from food and supplements. However, when you take vitamin D supplements in excessive amounts, typically over 4,000 IU per day, it can cause your intestines to absorb too much calcium. This leads to symptoms like nausea, vomiting, fatigue, and frequent urination. If left unchecked, long-term hypercalcemia from vitamin D supplementation can result in calcification of blood vessels, soft tissues, and even the kidneys, increasing your risk for cardiovascular complications and kidney damage.

2. Kidney Strain and Kidney Stones

   Overuse of vitamin D supplements can strain kidney function due to the body’s processing and excretion of excess calcium. High calcium levels in the urine, stimulated by elevated vitamin D, can contribute to the formation of kidney stones, particularly in individuals prone to calcium oxalate stones. In more severe cases, prolonged misuse of high-dose vitamin D supplements may lead to nephrocalcinosis, a condition in which calcium accumulates in kidney tissues, impairing kidney function. This is especially risky for people with pre-existing kidney disease.

3. Gastrointestinal Distress

   Some people may experience digestive discomfort as a side effect of vitamin D supplements, particularly when taken in large amounts or on an empty stomach. Symptoms can include bloating, nausea, constipation, or abdominal cramps. These reactions are typically mild and temporary, but they may indicate that the dosage of vitamin D supplements is too high or that your body is having difficulty adjusting. Switching to a different form (e.g., from tablet to softgel) or taking vitamin D supplements with food may help alleviate these symptoms.

4. Mood and Neurological Symptoms

   While adequate vitamin D levels support brain and mood health, taking excessive vitamin D supplements can sometimes have the opposite effect. Very high vitamin D levels may suppress parathyroid hormone (PTH) activity and disrupt calcium signaling in the nervous system, leading to symptoms like irritability, confusion, anxiety, or mental fog. These effects are rare and usually linked to vitamin D toxicity from high-dose, long-term supplementation.

5. Vitamin D Toxicity (Hypervitaminosis D)

   Vitamin D toxicity, also known as hypervitaminosis D, is a serious but rare condition that results from a consistently high intake of vitamin D supplements, usually doses well above 10,000 IU per day. Because vitamin D is fat-soluble, your body stores it in fat tissues, and it builds up over time instead of being excreted quickly like water-soluble vitamins. Symptoms of toxicity include severe nausea, vomiting, muscle weakness, dehydration, and elevated calcium levels. In extreme cases, it can cause irreversible kidney or cardiovascular damage.

How Did We Evaluate the Best Vitamin D Supplement For Women?

1. Brand Reputation

   NOW Foods stands out with the strongest reputation, earning an A+ rating from the BBB. Its long-standing presence, consistent quality, and responsive customer service make it a dependable option. Garden of Life follows closely with an A-rating and a good record of addressing customer issues, supporting its image as a clean-label, plant-based supplement brand.

   Thorne falls into the middle range with a C+ rating due to a handful of unresolved complaints, which is notable given its positioning as a premium, science-backed brand. Nature Made and Life Extension currently lacks BBB ratings, which limits visibility into their customer service practices. However, their established reputations and wide availability offer some level of confidence for buyers who prioritize familiarity and market presence.

   MaryRuth’s, Microingredients, and mindbodygreen rank lowest in overall reputation based on BBB ratings . MaryRuth’s holds an F rating with 15 complaints, 8 of which went unanswered. Microingredients also received an F rating, failing to respond to 5 out of 6 complaints. Mindbodygreen has a D- rating, with 4 complaints and no responses. These low scores reflect a consistent lack of accountability and poor customer service, serious concerns when evaluating supplements intended for daily, long-term use.

2. Value for Money

   We focused on value for money by comparing the cost per serving of these supplements, along with formulation quality and added functional benefits.

   Micro Ingredients Vitamin D3 K2 offers the strongest value at $23.95 for 180 softgels, combining D3 and K2 at just $0.13 per serving. Mary Ruth’s Megadose Liposomal follows closely, with enhanced absorption and around 225 servings for $18.95, about $0.09 per dose.

   Nature Made Vitamin D3 is another good budget-friendly option at $11.29 for 100 tablets, or $0.11 each, offering a straightforward, USP-verified option.

   Thorne’s Vitamin D-1, priced at $14 for 90 capsules ($0.16 per dose), brings trusted quality and clean formulation at a reasonable mid-range price.

   Life Extension’s combo of D3, K2, and iodine costs $18 for 60 capsules ($0.30 each), offering solid multi-nutrient value for women seeking more than just D3. NOW Vitamin D-3, at $7.99 for 30 softgels ($0.27 per dose), is a high-potency option better suited for short-term or targeted use rather than daily supplementation.

   Garden of Life’s Raw D3, with added probiotics and enzymes, costs $23.99 for 60 capsules, or $0.40 per dose, but the premium ingredients may be unnecessary for those just looking for Vitamin D.

   Mindbodygreen Vitamin D3 Potency+ is the least cost-effective at $30 for 30 softgels ($1 per serving). While it includes oils to aid absorption and clean-sourced ingredients, its premium price doesn’t match the value offered by more affordable, equally bioavailable alternatives.

Frequently Asked Questions

1. How do vitamin D supplements for women support immune function?
   Vitamin D supplements may help enhance immune function by activating receptors on immune cells, increasing antimicrobial peptides, and lowering inflammatory cytokines. This helps women reduce infection risk and supports immune balance, especially during hormonal shifts or periods of deficiency.
2. Why is vitamin K2 often paired with vitamin D in supplements for women’s vascular health?
   Vitamin K2 helps direct calcium, absorbed via vitamin D, into bones and away from arteries. This pairing could reduce the risk of vascular calcification and support cardiovascular and bone health, especially in postmenopausal women at higher risk.
3. Why is vitamin K2 crucial with high-dose vitamin D supplements for women?
   When women take high-dose vitamin D, K2 prevents calcium from accumulating in arteries. It activates proteins that guide calcium to bones, reducing cardiovascular risks and supporting skeletal health in aging or menopausal women.
4. How do high-dose vitamin D supplements enhance immune tolerance in women?
   High-dose vitamin D increases regulatory T cells and reduces inflammatory responses. This shift improves immune tolerance, helping women manage or prevent autoimmune conditions that are more prevalent in female populations.

Final Words

Vitamin D supplements may help improve bone density, support immune function, aid hormonal balance, and provide mental support. These supplements could support your daily routine, especially if you’re not getting enough vitamin D from sunlight or food sources such as fatty fish, egg yolks, or fortified dairy and plant-based products.

However, while vitamin D is essential, it’s important to approach supplementation with care. Excessive intake, particularly doses above 4,000 IU per day over extended periods, can lead to side effects. These may include nausea, vomiting, frequent urination, or elevated blood calcium levels (hypercalcemia), which in rare cases can contribute to kidney damage or calcification of soft tissues. These risks are most common when vitamin D is taken without monitoring blood levels or without professional guidance.

Personal factors also play a key role in determining your vitamin D needs. Women over 50, for example, may require higher doses (typically 800 IU daily or more) to help protect against age-related bone loss, especially after menopause. Women with darker skin tones or those living in northern regions may naturally produce less vitamin D from sun exposure, making supplementation even more important throughout the year. Those managing conditions like PCOS, autoimmune disorders, or malabsorption syndromes like celiac disease may need personalized support and medical oversight to address underlying deficiencies.

While most over-the-counter vitamin D supplements fall within the 600 to 2,000 IU range, levels that are generally safe for daily use, it’s always wise to tailor your intake based on a combination of lab testing, lifestyle, diet, and medical advice. Testing your vitamin D levels can provide a clearer picture of what your body truly needs and help you avoid the risks associated with both deficiency and excess.

The best vitamin D supplement is the one that aligns with your personal health goals and fits seamlessly into your routine without exceeding what your body requires. The eight supplements featured in this guide claim to offer quality, reliability, and thoughtful formulation to support your fitness safely and effectively. However, make sure to read the product label and consult the doctor before including them in your routine.