Is Vitamin D HSA/FSA Eligible? Yes, Here's How!

Why vitamin D qualifies for HSA/FSA

If your doctor has diagnosed vitamin D deficiency, a supplement puts back a nutrient your body is missing. Your Letter of Medical Necessity (LMN) records your provider's recommendation and ties that bottle to your condition.

IRS Publication 502 defines medical expenses to include the “diagnosis, cure, mitigation, treatment, or prevention of disease.” Its Nutritional Supplements entry counts vitamins as medical expenses when they are recommended by a medical practitioner as treatment for a specific medical condition diagnosed by a physician.

The LMN is that written recommendation. It identifies the condition and explains why vitamin D belongs in your care. The same rule applies whether the bottle says vitamin D or vitamin D3.

This page covers vitamin D specifically. Our vitamins and supplements HSA/FSA guide covers the wider supplement aisle.

Health conditions that support a vitamin D LMN

Vitamin D helps your body absorb calcium, giving it a direct role in bone health. Your provider might tie your supplement to a diagnosed deficiency, a bone condition or another specific reason in your medical history. Here are some of the common conditions a provider can document:

• Vitamin D deficiency. Replacing missing vitamin D is the most direct reason for a supplement. MedlinePlus identifies supplements as the way to address deficiency, with your provider deciding how much, how often and for how long.
• Osteoporosis. An osteoporosis plan leans on calcium, and vitamin D helps your body take it in. NIAMS includes calcium and vitamin D in osteoporosis care, including supplements when needed to reach the recommended intake.
• Osteomalacia related to vitamin D deficiency. This condition softens adult bones. MedlinePlus describes oral vitamin D, calcium and phosphorus supplements as part of care, so vitamin D has a clear job: helping your body absorb the calcium your bones need to harden.
• Nutritional rickets. Growing bones can soften and weaken when a child lacks vitamin D, calcium or phosphate. MedlinePlus explains that replacing those nutrients helps correct nutritional rickets. Your child can have their own letter for the vitamin D their provider recommends.
• Recurrent benign paroxysmal positional vertigo (BPPV) with low vitamin D. Vitamin D is involved in how your body handles calcium, including in the parts of your inner ear that keep your balance. A 2025 systematic review in Frontiers in Neurology found that people taking vitamin D had BPPV come back less often than comparison groups did.

Not on this list? Vitamin D still counts when your provider recommends it for another health condition you have.

How to get your Letter of Medical Necessity for vitamin D

You can get your vitamin D letter two ways, through Crates or your own doctor.

• Through Crates, typically in under 24 hours. Getting a vitamin D letter starts with a short online health assessment that takes about 2 to 3 minutes. A licensed provider reviews it, and if you qualify, your letter is issued for vitamin D. Your letter stays valid for 12 months and renews each year.
• Through your own doctor, a few days to a few weeks. Book a visit and say you want to use HSA/FSA funds for vitamin D. Ask your doctor to put in writing how vitamin D helps prevent, manage, or reverse your condition. Check that your doctor's letter is signed and dated; a copay is possible for the visit.

How to buy vitamin D with HSA/FSA funds

Once your letter is ready, shop for vitamin D online or in a store, then get your money back.

1. Get your LMN first. Pick Crates or your own doctor (see above) and have the letter in hand before you buy.
2. Buy the vitamin D anywhere. Pay with your personal card and keep the itemized receipt showing the product, purchase date and amount paid. If your order includes other items, save the breakdown showing the vitamin D charge.
3. Get your funds back. Then use one-click reimbursement so Crates files your claim, or upload the letter and receipt yourself. For an HSA, keep both with your tax records and reimburse yourself from the account.

An HSA only covers purchases made after you opened it, and an FSA only covers purchases within your coverage dates, as Publication 969 explains. Our HSA vs. FSA guide covers the account differences.

Which vitamin D supplements are HSA/FSA eligible?

Any brand, any format: the letter covers vitamin D for your condition, whichever bottle you choose. Just buy the one your provider recommends, whether that's a D3 softgel, liquid drops or a calcium-and-vitamin-D combo.

NIH describes two forms of vitamin D in supplements: D3, called cholecalciferol, and D2, called ergocalciferol. Both increase vitamin D levels in the blood. Softgels, gummies and drops are just different ways to take it; the eligibility rule stays the same.

Vitamin D is a vitamin supplement, so it qualifies through your letter.

Any brand follows that same rule. If you are considering Thorne, our Thorne HSA/FSA guide covers its supplements. Buying other supplements in the same order? Our magnesium and fish oil guides explain their eligibility separately.

How much can you save on vitamin D?

Paying with HSA/FSA money means paying with untaxed dollars, which works out to savings of up to 30% on vitamin D. For example, $120 of vitamin D over a year saves you $36 in taxes when your combined rate is roughly 30%. That rate can include federal and state income taxes, plus payroll taxes where applicable.

Each column multiplies the purchase price by the illustrated tax rate:

These are illustrative annual totals, not current bottle prices or retailer discounts. The store still charges its usual price, and you're reimbursed from your own account. The exact figure depends on your own taxes and how you fund the account; provider or LMN fees are separate.